TY  - JOUR
AU  - Abubaker, Ahmed
AU  - Kostić, Ivan
AU  - Kostić, Olivera
AU  - Stefanović, Zoran
PY  - 2018
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2890
AB  - Wind tunnel tests of wind influence on ground objects require proper experimental modeling of the atmospheric boundary layer (ABL). The authors have performed computational analyses with an aim to establish a reliable computational algorithm that could resemble complex flow patterns in wind tunnels with various obstacles, used to simulate appropriate velocity profiles within the ABL. For experimental verifications, measurements from two experimental facilities were applied, with speeds ranging from 1-4 m/s in the first, and 45 m/s in the second. For all considered cases, good agreements between the measured and computed speed profiles for operational engineering purposes have been achieved. In the sense of qualitative analyses, calculated contours of velocity magnitude and eddy viscosity inside the wind tunnel test sections have verified that good homogeneity of the simulated ABL in both wind tunnels had been established in the domains where velocity profiles were measured. Presented results have shown the capability of here established calculation model to resemble a number of costly wind tunnel test hours during preparations of proper obstacle arrangements for experimental ABL modeling in a wide wind speed range, and thus reduce the overall project costs. Also, presented CFD algorithm can readily be calibrated and used for engineering research of wind effects on different ground objects, as a virtual wind tunnel.
PB  - Univ Osijek, Tech Fac, Slavonski Brod
T2  - Tehnički vjesnik
T1  - CFD Modeling of Atmospheric Boundary Layer Simulations in Wind Tunnels
EP  - 1602
IS  - 6
SP  - 1595
VL  - 25
DO  - 10.17559/TV-20161125134410
ER  - 

@article{
author = "Abubaker, Ahmed and Kostić, Ivan and Kostić, Olivera and Stefanović, Zoran",
year = "2018",
abstract = "Wind tunnel tests of wind influence on ground objects require proper experimental modeling of the atmospheric boundary layer (ABL). The authors have performed computational analyses with an aim to establish a reliable computational algorithm that could resemble complex flow patterns in wind tunnels with various obstacles, used to simulate appropriate velocity profiles within the ABL. For experimental verifications, measurements from two experimental facilities were applied, with speeds ranging from 1-4 m/s in the first, and 45 m/s in the second. For all considered cases, good agreements between the measured and computed speed profiles for operational engineering purposes have been achieved. In the sense of qualitative analyses, calculated contours of velocity magnitude and eddy viscosity inside the wind tunnel test sections have verified that good homogeneity of the simulated ABL in both wind tunnels had been established in the domains where velocity profiles were measured. Presented results have shown the capability of here established calculation model to resemble a number of costly wind tunnel test hours during preparations of proper obstacle arrangements for experimental ABL modeling in a wide wind speed range, and thus reduce the overall project costs. Also, presented CFD algorithm can readily be calibrated and used for engineering research of wind effects on different ground objects, as a virtual wind tunnel.",
publisher = "Univ Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnički vjesnik",
title = "CFD Modeling of Atmospheric Boundary Layer Simulations in Wind Tunnels",
pages = "1602-1595",
number = "6",
volume = "25",
doi = "10.17559/TV-20161125134410"
}

Abubaker, A., Kostić, I., Kostić, O.,& Stefanović, Z.. (2018). CFD Modeling of Atmospheric Boundary Layer Simulations in Wind Tunnels. in Tehnički vjesnik
Univ Osijek, Tech Fac, Slavonski Brod., 25(6), 1595-1602.
https://doi.org/10.17559/TV-20161125134410

Abubaker A, Kostić I, Kostić O, Stefanović Z. CFD Modeling of Atmospheric Boundary Layer Simulations in Wind Tunnels. in Tehnički vjesnik. 2018;25(6):1595-1602.
doi:10.17559/TV-20161125134410 .

Abubaker, Ahmed, Kostić, Ivan, Kostić, Olivera, Stefanović, Zoran, "CFD Modeling of Atmospheric Boundary Layer Simulations in Wind Tunnels" in Tehnički vjesnik, 25, no. 6 (2018):1595-1602,
https://doi.org/10.17559/TV-20161125134410 . .

TY  - JOUR
AU  - Kostić, Olivera
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
PY  - 2017
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2579
AB  - In this study, a CFD (Computational Fluid Dynamics) computational model has been established, with the aim to properly simulate complex supersonic flow generated by a 2D convergent-divergent nozzle. For the purpose of rocket engine thrust vector control (TVC) simulations, initially several jet tab positions were used to generate up to 30% shadowing of the nozzle exit, without and with a gap between tab and exit. Numerical results were compared with the existing experimental data, both quantitatively and qualitatively, and fair agreements have been obtained in both senses. The same CFD settings have then been applied for the computational analysis of another TVC type - the jet vane, which was analysed in four different adopted configurations with respect to the nozzle. Stable convergence of solutions has been achieved, up to 40 degrees of vane deflections. Performed calculations have enabled comparisons of the two considered TVC types, in the sense of the achieved thrust force deflections, and thrust losses.
PB  - Univ Osijek, Tech Fac, Slavonski Brod
T2  - Tehnički vjesnik
T1  - Comparative cfd analyses of a 2d supersonic nozzle flow with jet tab and jet vane
EP  - 1344
IS  - 5
SP  - 1335
VL  - 24
DO  - 10.17559/TV-20160208145336
ER  - 

@article{
author = "Kostić, Olivera and Stefanović, Zoran and Kostić, Ivan",
year = "2017",
abstract = "In this study, a CFD (Computational Fluid Dynamics) computational model has been established, with the aim to properly simulate complex supersonic flow generated by a 2D convergent-divergent nozzle. For the purpose of rocket engine thrust vector control (TVC) simulations, initially several jet tab positions were used to generate up to 30% shadowing of the nozzle exit, without and with a gap between tab and exit. Numerical results were compared with the existing experimental data, both quantitatively and qualitatively, and fair agreements have been obtained in both senses. The same CFD settings have then been applied for the computational analysis of another TVC type - the jet vane, which was analysed in four different adopted configurations with respect to the nozzle. Stable convergence of solutions has been achieved, up to 40 degrees of vane deflections. Performed calculations have enabled comparisons of the two considered TVC types, in the sense of the achieved thrust force deflections, and thrust losses.",
publisher = "Univ Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnički vjesnik",
title = "Comparative cfd analyses of a 2d supersonic nozzle flow with jet tab and jet vane",
pages = "1344-1335",
number = "5",
volume = "24",
doi = "10.17559/TV-20160208145336"
}

Kostić, O., Stefanović, Z.,& Kostić, I.. (2017). Comparative cfd analyses of a 2d supersonic nozzle flow with jet tab and jet vane. in Tehnički vjesnik
Univ Osijek, Tech Fac, Slavonski Brod., 24(5), 1335-1344.
https://doi.org/10.17559/TV-20160208145336

Kostić O, Stefanović Z, Kostić I. Comparative cfd analyses of a 2d supersonic nozzle flow with jet tab and jet vane. in Tehnički vjesnik. 2017;24(5):1335-1344.
doi:10.17559/TV-20160208145336 .

Kostić, Olivera, Stefanović, Zoran, Kostić, Ivan, "Comparative cfd analyses of a 2d supersonic nozzle flow with jet tab and jet vane" in Tehnički vjesnik, 24, no. 5 (2017):1335-1344,
https://doi.org/10.17559/TV-20160208145336 . .

TY  - JOUR
AU  - Linić, Suzana
AU  - Ristić, Slavica
AU  - Stefanović, Zoran
AU  - Kozić, Mirko
AU  - Ocokoljić, Goran
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2060
AB  - Rad predstavlja eksperimentalno i numeričko istraživanje modela sfere sa ciljem predviđanja ponašanja strujanja u prisustvu hrapavosti površina. Rezultati ukazuju na probleme i predlažu rešenje za inžinjersku primenu. Sličnost između strujnih slika dobijenih numeričkim putem i u aerotunelu je postignuta kombinovanim uvođenjem turbulencije u numeričkoj slobodnoj struji hrapavosti površine, zbog ograničavajućih zahteva turbulentnih modela.
AB  - This paper presents the experimental and numerical research on the sphere model with the goal of prediction of a flow behaviour in a presence of the surface roughness. Results indicate the problems and suggest the solution for engineering practice. The similarity of the numerical and wind tunnel flows was reached by an application of a combination of the intentionally introduced turbulence intensity in a numerical flow as well the artificial roughness of the model, for a reason of restricted requirements of the turbulence modelling.
PB  - Vojnotehnički institut, Beograd
T2  - Scientific Technical Review
T1  - Eksperimentalno i numeričko istraživanje nadkritičnog strujanja oko hrapave kugle
T1  - Ëksperimental'noe i čislennoe issledovanie sverhkritičeskogo obtekanija šerohovatyh šarov / (francuski) Recherches expérimentales et numériques du courant super critique autour d'une sphère rugueuse
T1  - Experimental and numerical study of super-critical flow around the rough sphere
EP  - 19
IS  - 2
SP  - 11
VL  - 65
DO  - 10.5937/STR1502011L
ER  - 

@article{
author = "Linić, Suzana and Ristić, Slavica and Stefanović, Zoran and Kozić, Mirko and Ocokoljić, Goran",
year = "2015",
abstract = "Rad predstavlja eksperimentalno i numeričko istraživanje modela sfere sa ciljem predviđanja ponašanja strujanja u prisustvu hrapavosti površina. Rezultati ukazuju na probleme i predlažu rešenje za inžinjersku primenu. Sličnost između strujnih slika dobijenih numeričkim putem i u aerotunelu je postignuta kombinovanim uvođenjem turbulencije u numeričkoj slobodnoj struji hrapavosti površine, zbog ograničavajućih zahteva turbulentnih modela., This paper presents the experimental and numerical research on the sphere model with the goal of prediction of a flow behaviour in a presence of the surface roughness. Results indicate the problems and suggest the solution for engineering practice. The similarity of the numerical and wind tunnel flows was reached by an application of a combination of the intentionally introduced turbulence intensity in a numerical flow as well the artificial roughness of the model, for a reason of restricted requirements of the turbulence modelling.",
publisher = "Vojnotehnički institut, Beograd",
journal = "Scientific Technical Review",
title = "Eksperimentalno i numeričko istraživanje nadkritičnog strujanja oko hrapave kugle, Ëksperimental'noe i čislennoe issledovanie sverhkritičeskogo obtekanija šerohovatyh šarov / (francuski) Recherches expérimentales et numériques du courant super critique autour d'une sphère rugueuse, Experimental and numerical study of super-critical flow around the rough sphere",
pages = "19-11",
number = "2",
volume = "65",
doi = "10.5937/STR1502011L"
}

Linić, S., Ristić, S., Stefanović, Z., Kozić, M.,& Ocokoljić, G.. (2015). Eksperimentalno i numeričko istraživanje nadkritičnog strujanja oko hrapave kugle. in Scientific Technical Review
Vojnotehnički institut, Beograd., 65(2), 11-19.
https://doi.org/10.5937/STR1502011L

Linić S, Ristić S, Stefanović Z, Kozić M, Ocokoljić G. Eksperimentalno i numeričko istraživanje nadkritičnog strujanja oko hrapave kugle. in Scientific Technical Review. 2015;65(2):11-19.
doi:10.5937/STR1502011L .

Linić, Suzana, Ristić, Slavica, Stefanović, Zoran, Kozić, Mirko, Ocokoljić, Goran, "Eksperimentalno i numeričko istraživanje nadkritičnog strujanja oko hrapave kugle" in Scientific Technical Review, 65, no. 2 (2015):11-19,
https://doi.org/10.5937/STR1502011L . .

TY  - JOUR
AU  - Abdullah, Taha Ahmed
AU  - Petrović, Zlatko
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
AU  - Isaković, Jovan
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2246
AB  - The correction method for pressure coefficient distribution around an airfoil is developed for the purpose of the postprocessing of wind tunnel data, obtained from the model pressure measurements. Pressure coefficient distribution around the airfoil, directly obtained by wind tunnel measurements, is corrected numerically in order to compensate for the interference effects of the wind tunnel test section walls. In this paper, the airfoil NACA0012 is approximated by linear vortex segments, which are then mirrored using sufficient number of images with respect to the ceiling and the floor of the test section, to model the flow pattern around an airfoil in the wind tunnel test section with solid walls. Flow calculations, both with the tunnel wall presence and in the free stream, are then performed. The numerically obtained pressure coefficient difference between these two cases should be superimposed to the pressure coefficient distribution measured in the wind tunnel, for the same nominal airflow parameters and angle of attack, at the corresponding points, resulting in the corrected experimental pressure coefficient distribution. The values of corrections generally increase with the reduction of the wind tunnel test section relative height. The paper is focused on the verification of lift curve slope corrections, where very good agreements have been obtained with several well-known classical correction methods.
PB  - Univ Osijek, Tech Fac, Slavonski Brod
T2  - Tehnički vjesnik
T1  - Two-dimensional wind tunnel measurement corrections by the singularity method
EP  - 565
IS  - 3
SP  - 557
VL  - 22
DO  - 10.17559/TV-20140214114718
ER  - 

@article{
author = "Abdullah, Taha Ahmed and Petrović, Zlatko and Stefanović, Zoran and Kostić, Ivan and Isaković, Jovan",
year = "2015",
abstract = "The correction method for pressure coefficient distribution around an airfoil is developed for the purpose of the postprocessing of wind tunnel data, obtained from the model pressure measurements. Pressure coefficient distribution around the airfoil, directly obtained by wind tunnel measurements, is corrected numerically in order to compensate for the interference effects of the wind tunnel test section walls. In this paper, the airfoil NACA0012 is approximated by linear vortex segments, which are then mirrored using sufficient number of images with respect to the ceiling and the floor of the test section, to model the flow pattern around an airfoil in the wind tunnel test section with solid walls. Flow calculations, both with the tunnel wall presence and in the free stream, are then performed. The numerically obtained pressure coefficient difference between these two cases should be superimposed to the pressure coefficient distribution measured in the wind tunnel, for the same nominal airflow parameters and angle of attack, at the corresponding points, resulting in the corrected experimental pressure coefficient distribution. The values of corrections generally increase with the reduction of the wind tunnel test section relative height. The paper is focused on the verification of lift curve slope corrections, where very good agreements have been obtained with several well-known classical correction methods.",
publisher = "Univ Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnički vjesnik",
title = "Two-dimensional wind tunnel measurement corrections by the singularity method",
pages = "565-557",
number = "3",
volume = "22",
doi = "10.17559/TV-20140214114718"
}

Abdullah, T. A., Petrović, Z., Stefanović, Z., Kostić, I.,& Isaković, J.. (2015). Two-dimensional wind tunnel measurement corrections by the singularity method. in Tehnički vjesnik
Univ Osijek, Tech Fac, Slavonski Brod., 22(3), 557-565.
https://doi.org/10.17559/TV-20140214114718

Abdullah TA, Petrović Z, Stefanović Z, Kostić I, Isaković J. Two-dimensional wind tunnel measurement corrections by the singularity method. in Tehnički vjesnik. 2015;22(3):557-565.
doi:10.17559/TV-20140214114718 .

Abdullah, Taha Ahmed, Petrović, Zlatko, Stefanović, Zoran, Kostić, Ivan, Isaković, Jovan, "Two-dimensional wind tunnel measurement corrections by the singularity method" in Tehnički vjesnik, 22, no. 3 (2015):557-565,
https://doi.org/10.17559/TV-20140214114718 . .

TY  - JOUR
AU  - Sekutkovski, Bojan
AU  - Kostić, Ivan
AU  - Stefanović, Zoran
AU  - Simonović, Aleksandar
AU  - Kostić, Olivera
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2245
AB  - Three-dimensional, compressible, viscous and transient transonic turbulent flow over the wing was simulated by a hybrid RANS-LES modelling method, combined with the compressible k-omegaSSTSAS turbulence model. This approach is based on dividing the contribution of the fluctuating and the averaged velocity fields in the subgrid tensor, and modelling each of them with its corresponding turbulent viscosity. The "RANS mode" is used in flow field domains which can be treated with acceptable accuracy as relatively steady, such as in the boundary layer, while the "LES mode" is applied in the dominantly unsteady regions, far from the wing. Discretization of the governing equations is performed by Finite Volume Method on unstructured mesh. The method has been verified on the Onera M6 wing. The parallelization is achieved by decomposing the mesh into sub-domains and using the Open MPI technology. The implementation of turbulence model has been done using OpenFOAM. The flow simulation was also performed using ANSYS Fluent, and the results of the two methods were compared mutually, and with the Onera M6 experiment.
PB  - Univ Osijek, Tech Fac, Slavonski Brod
T2  - Tehnički vjesnik
T1  - A hybrid rans-les method with compressible k-omegasstsas turbulence model for high reynolds number flow applications
EP  - 1245
IS  - 5
SP  - 1237
VL  - 22
DO  - 10.17559/TV-20140404130058
ER  - 

@article{
author = "Sekutkovski, Bojan and Kostić, Ivan and Stefanović, Zoran and Simonović, Aleksandar and Kostić, Olivera",
year = "2015",
abstract = "Three-dimensional, compressible, viscous and transient transonic turbulent flow over the wing was simulated by a hybrid RANS-LES modelling method, combined with the compressible k-omegaSSTSAS turbulence model. This approach is based on dividing the contribution of the fluctuating and the averaged velocity fields in the subgrid tensor, and modelling each of them with its corresponding turbulent viscosity. The "RANS mode" is used in flow field domains which can be treated with acceptable accuracy as relatively steady, such as in the boundary layer, while the "LES mode" is applied in the dominantly unsteady regions, far from the wing. Discretization of the governing equations is performed by Finite Volume Method on unstructured mesh. The method has been verified on the Onera M6 wing. The parallelization is achieved by decomposing the mesh into sub-domains and using the Open MPI technology. The implementation of turbulence model has been done using OpenFOAM. The flow simulation was also performed using ANSYS Fluent, and the results of the two methods were compared mutually, and with the Onera M6 experiment.",
publisher = "Univ Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnički vjesnik",
title = "A hybrid rans-les method with compressible k-omegasstsas turbulence model for high reynolds number flow applications",
pages = "1245-1237",
number = "5",
volume = "22",
doi = "10.17559/TV-20140404130058"
}

Sekutkovski, B., Kostić, I., Stefanović, Z., Simonović, A.,& Kostić, O.. (2015). A hybrid rans-les method with compressible k-omegasstsas turbulence model for high reynolds number flow applications. in Tehnički vjesnik
Univ Osijek, Tech Fac, Slavonski Brod., 22(5), 1237-1245.
https://doi.org/10.17559/TV-20140404130058

Sekutkovski B, Kostić I, Stefanović Z, Simonović A, Kostić O. A hybrid rans-les method with compressible k-omegasstsas turbulence model for high reynolds number flow applications. in Tehnički vjesnik. 2015;22(5):1237-1245.
doi:10.17559/TV-20140404130058 .

Sekutkovski, Bojan, Kostić, Ivan, Stefanović, Zoran, Simonović, Aleksandar, Kostić, Olivera, "A hybrid rans-les method with compressible k-omegasstsas turbulence model for high reynolds number flow applications" in Tehnički vjesnik, 22, no. 5 (2015):1237-1245,
https://doi.org/10.17559/TV-20140404130058 . .

TY  - JOUR
AU  - Kostić, Olivera
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2149
AB  - Modeliranje složenih nadzvučnih strujnih polja korišćenjem računara predstavlja jedan od najvećih izazova u oblasti CFD analiza. U radu su predstavljeni prvi koraci u numeričkoj analizi takvog strujanja, generisanog konvergentno- divergentnim mlaznikom sa Mahovim brojem M = 2.6 na izlazu iz mlaznika. Cilj je bio postići dobra poklapanja sa raspoloživim eksperimentalnim podacima, dobijenim tokom ispitivanja u nadzvučnom aerotunelu instituta VTI Žarkovo, gde su ispitivane mogućnosti vektorisanja potiska mlaznika sa vazduhom kao radnim fluidom, postavljanjem različitih tipova prepreka na izlazu iza mlaznika. U radu se analiziraju slučajevi strujanja sa slobodnim izlazom i sa jednim izabranim tipom prepreke na izlazu iz mlaznika. Za oba slučaja korišćene su strukturirane proračunske mreže za rešavanje RANS jednačina sa k-w SST turbulentnim modelom. Nakon kvalitativnih i kvantitativnih poređenja sa raspoloživim eksperimentalnim rezultatima, utvrđena su dobra poklapanja, pri čemu je CFD analiza bila u mogućnosti da pruži i dodatne podatke o strujnom polju, koji nisu mereni tokom eksperimenata.
AB  - Computational modeling of complex supersonic airflow patterns is one of the greatest challenges in the domain of CFD analyses. The paper presents initial steps in numerical analysis of such flow, generated by convergentdivergent nozzle with Mach number M = 2.6 at nozzle exit. The aim was to achieve good agreements with available experimental data, obtained during supersonic wind tunnel tests at VTI Žarkovo institute, where nozzle thrust vectoring possibilities had been investigated using air as test fluid, by placing different types of obstacles at the exit section. Paper is focussed on free exit flow, and flow with one selected obstacle type. Using structured mesh for both cases, the RANS equations with k-w SST turbulent model have been applied. After quantitative and qualitative comparisons with available experimental data, good agreements have been obtained, where CFD was also able to provide additional flowfield data, not measuted during experiments.
PB  - Univerzitet u Beogradu - Mašinski fakultet, Beograd
T2  - FME Transactions
T1  - CFD modeliranje nadzvučne vazdušne struje generisane 2D mlaznikom sa preprekom i bez prepreke na izlazu
T1  - CFD modeling of supersonic airflow generated by 2D nozzle with and without an obstacle at the exit section
EP  - 113
IS  - 2
SP  - 107
VL  - 43
DO  - 10.5937/fmet1502107K
ER  - 

@article{
author = "Kostić, Olivera and Stefanović, Zoran and Kostić, Ivan",
year = "2015",
abstract = "Modeliranje složenih nadzvučnih strujnih polja korišćenjem računara predstavlja jedan od najvećih izazova u oblasti CFD analiza. U radu su predstavljeni prvi koraci u numeričkoj analizi takvog strujanja, generisanog konvergentno- divergentnim mlaznikom sa Mahovim brojem M = 2.6 na izlazu iz mlaznika. Cilj je bio postići dobra poklapanja sa raspoloživim eksperimentalnim podacima, dobijenim tokom ispitivanja u nadzvučnom aerotunelu instituta VTI Žarkovo, gde su ispitivane mogućnosti vektorisanja potiska mlaznika sa vazduhom kao radnim fluidom, postavljanjem različitih tipova prepreka na izlazu iza mlaznika. U radu se analiziraju slučajevi strujanja sa slobodnim izlazom i sa jednim izabranim tipom prepreke na izlazu iz mlaznika. Za oba slučaja korišćene su strukturirane proračunske mreže za rešavanje RANS jednačina sa k-w SST turbulentnim modelom. Nakon kvalitativnih i kvantitativnih poređenja sa raspoloživim eksperimentalnim rezultatima, utvrđena su dobra poklapanja, pri čemu je CFD analiza bila u mogućnosti da pruži i dodatne podatke o strujnom polju, koji nisu mereni tokom eksperimenata., Computational modeling of complex supersonic airflow patterns is one of the greatest challenges in the domain of CFD analyses. The paper presents initial steps in numerical analysis of such flow, generated by convergentdivergent nozzle with Mach number M = 2.6 at nozzle exit. The aim was to achieve good agreements with available experimental data, obtained during supersonic wind tunnel tests at VTI Žarkovo institute, where nozzle thrust vectoring possibilities had been investigated using air as test fluid, by placing different types of obstacles at the exit section. Paper is focussed on free exit flow, and flow with one selected obstacle type. Using structured mesh for both cases, the RANS equations with k-w SST turbulent model have been applied. After quantitative and qualitative comparisons with available experimental data, good agreements have been obtained, where CFD was also able to provide additional flowfield data, not measuted during experiments.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet, Beograd",
journal = "FME Transactions",
title = "CFD modeliranje nadzvučne vazdušne struje generisane 2D mlaznikom sa preprekom i bez prepreke na izlazu, CFD modeling of supersonic airflow generated by 2D nozzle with and without an obstacle at the exit section",
pages = "113-107",
number = "2",
volume = "43",
doi = "10.5937/fmet1502107K"
}

Kostić, O., Stefanović, Z.,& Kostić, I.. (2015). CFD modeliranje nadzvučne vazdušne struje generisane 2D mlaznikom sa preprekom i bez prepreke na izlazu. in FME Transactions
Univerzitet u Beogradu - Mašinski fakultet, Beograd., 43(2), 107-113.
https://doi.org/10.5937/fmet1502107K

Kostić O, Stefanović Z, Kostić I. CFD modeliranje nadzvučne vazdušne struje generisane 2D mlaznikom sa preprekom i bez prepreke na izlazu. in FME Transactions. 2015;43(2):107-113.
doi:10.5937/fmet1502107K .

Kostić, Olivera, Stefanović, Zoran, Kostić, Ivan, "CFD modeliranje nadzvučne vazdušne struje generisane 2D mlaznikom sa preprekom i bez prepreke na izlazu" in FME Transactions, 43, no. 2 (2015):107-113,
https://doi.org/10.5937/fmet1502107K . .

TY  - JOUR
AU  - Benisa, Muamar
AU  - Babić, Bojan
AU  - Grbović, Aleksandar
AU  - Stefanović, Zoran
PY  - 2014
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1935
AB  - Pri proizvodnji novog dela može se primeniti pristup probnih pokušaja u cilju dobijanja dela bez defekata, a to u velikoj meri zavisi od iskustva radnika. U ovoj fazi iskustvo projektanta i proizvođača treba da pruži važnu podršku za smanjenje broja pokušaja i samim tim doprinese minimizaciji vremena odziva i troškova uz maksimizaciju ujednačenosti proizvoda. Obrada lima u alatima sa gumenim jezgrom značajno unapređuje formabilnost pripremka zbog toga što su kontaktne površine između krutog dela alata i dela alata sa gumenim jezgrom fleksibilne. Ovaj metod omogućava izradu delova od lima sa kompleksnim konturama uz relativno male troškove zbog toga što je potreban samo jedan deo alata od čvrstog materijala. U avio industriji proizvode se delovi od lima u malim količinama tako da se ne isplate veće investicije u alate i projektovanje procesa. Iz ovih razloga neophodna je primena simulacija tehnološkog procesa metodom konačnih elemenata tokom konceptualnog projektovanja.
AB  - To produce a new component there are a trial and error stage to obtain a part without defects, which strongly depends on operator's experience. At this stage, the experience of designer and manufacturers should give an important aid to reduce trials to realize the minimization of response time and cost with maximization of the product equality. Rubber pad forming highly improves the formability of the blank because the contact surfaces between the rigid die and the rubber pad is flexible. This method enables to produce sheet metal components with complex contour by relatively low cost because only one rigid die is required. However, in aerospace field, parts are produced in small sheet metal bending and small number of components. It means that it is not worthy for large investments in tools and process design. For these reasons, it is necessary to use FE simulation of manufacturing process during the conceptual design.
PB  - Univerzitet u Beogradu - Mašinski fakultet, Beograd
T2  - FME Transactions
T1  - Numerička simulacija kao alat za optimizaciju geometrije alata za procese obrade lima u alatima sa gumenim jezgrom
T1  - Numerical simulation as a tool for optimizing tool geometry for rubber pad forming process
EP  - 73
IS  - 1
SP  - 67
VL  - 42
DO  - 10.5937/fmet1401067B
ER  - 

@article{
author = "Benisa, Muamar and Babić, Bojan and Grbović, Aleksandar and Stefanović, Zoran",
year = "2014",
abstract = "Pri proizvodnji novog dela može se primeniti pristup probnih pokušaja u cilju dobijanja dela bez defekata, a to u velikoj meri zavisi od iskustva radnika. U ovoj fazi iskustvo projektanta i proizvođača treba da pruži važnu podršku za smanjenje broja pokušaja i samim tim doprinese minimizaciji vremena odziva i troškova uz maksimizaciju ujednačenosti proizvoda. Obrada lima u alatima sa gumenim jezgrom značajno unapređuje formabilnost pripremka zbog toga što su kontaktne površine između krutog dela alata i dela alata sa gumenim jezgrom fleksibilne. Ovaj metod omogućava izradu delova od lima sa kompleksnim konturama uz relativno male troškove zbog toga što je potreban samo jedan deo alata od čvrstog materijala. U avio industriji proizvode se delovi od lima u malim količinama tako da se ne isplate veće investicije u alate i projektovanje procesa. Iz ovih razloga neophodna je primena simulacija tehnološkog procesa metodom konačnih elemenata tokom konceptualnog projektovanja., To produce a new component there are a trial and error stage to obtain a part without defects, which strongly depends on operator's experience. At this stage, the experience of designer and manufacturers should give an important aid to reduce trials to realize the minimization of response time and cost with maximization of the product equality. Rubber pad forming highly improves the formability of the blank because the contact surfaces between the rigid die and the rubber pad is flexible. This method enables to produce sheet metal components with complex contour by relatively low cost because only one rigid die is required. However, in aerospace field, parts are produced in small sheet metal bending and small number of components. It means that it is not worthy for large investments in tools and process design. For these reasons, it is necessary to use FE simulation of manufacturing process during the conceptual design.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet, Beograd",
journal = "FME Transactions",
title = "Numerička simulacija kao alat za optimizaciju geometrije alata za procese obrade lima u alatima sa gumenim jezgrom, Numerical simulation as a tool for optimizing tool geometry for rubber pad forming process",
pages = "73-67",
number = "1",
volume = "42",
doi = "10.5937/fmet1401067B"
}

Benisa, M., Babić, B., Grbović, A.,& Stefanović, Z.. (2014). Numerička simulacija kao alat za optimizaciju geometrije alata za procese obrade lima u alatima sa gumenim jezgrom. in FME Transactions
Univerzitet u Beogradu - Mašinski fakultet, Beograd., 42(1), 67-73.
https://doi.org/10.5937/fmet1401067B

Benisa M, Babić B, Grbović A, Stefanović Z. Numerička simulacija kao alat za optimizaciju geometrije alata za procese obrade lima u alatima sa gumenim jezgrom. in FME Transactions. 2014;42(1):67-73.
doi:10.5937/fmet1401067B .

Benisa, Muamar, Babić, Bojan, Grbović, Aleksandar, Stefanović, Zoran, "Numerička simulacija kao alat za optimizaciju geometrije alata za procese obrade lima u alatima sa gumenim jezgrom" in FME Transactions, 42, no. 1 (2014):67-73,
https://doi.org/10.5937/fmet1401067B . .

TY  - JOUR
AU  - Kostić, Ivan
AU  - Stefanović, Zoran
AU  - Kostić, Olivera
PY  - 2014
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2000
AB  - Tokom aerodinamičkog projektovanja aviona, shodno njegovoj kategoriji i fazi razvoja projekta, potrebno je koristiti adekvatne proračunske metode i softverske alate. U slučaju lakih aviona, uobičajeno se koriste analitičke i semiempirijske metode u inicijalnoj fazi, kombinovane sa jednostavnim - neviskoznim CFD proračunskim modelima, dok se u kasnijim fazama obavljaju relativno kompleksne CFD analize sa uticajem viskoznosti. U današnje vreme se, u kategoriji lakih aviona, podrazumeva da savremeni proračunski alati za svaku od faza razvoja moraju biti adekvatno izabrani, tako da se njima dobijeni rezultati međusobno verifikuju i dopunjavaju. U radu su prikazane proračunske metode korišćene tokom aerodinamičke analize novog lakog aviona u različitim fazama njegovog razvoja i izvršeno je poređenje dobijenih rezultata, u cilju verifikacije ispunjenja navedenog uslova.
AB  - During the evolution of an airplane aerodynamic design, proper calculation methods and software tools should be utilized, which correspond to the airplane category and project development level. In case of light aircraft, the general trend is the application of analytical and semiempirical methods at the initial stages, combined with simplified - inviscid CFD computational models, and fairly complex viscous CFD analyses at higher design levels. At the present stage of light aviation development, it is assumed that the contemporary design tools for each of those steps should be appropriate enough, so that they actually verify and additionally fine-tune each other's results. This paper describes the calculation tools and methods applied during the aerodynamic analyses of a new light aircraft at different development stages, and compares the results obtained by them, with the aim to verify and support the above statement, considering light aircraft aerodynamic design.
PB  - Univerzitet u Beogradu - Mašinski fakultet, Beograd
T2  - FME Transactions
T1  - Aerodinamička analiza lakog aviona u različitim razvojnim fazama projekta
T1  - Aerodynamic analysis of a light aircraft at different design stages
EP  - 105
IS  - 2
SP  - 94
VL  - 42
DO  - 10.5937/fmet1402094K
ER  - 

@article{
author = "Kostić, Ivan and Stefanović, Zoran and Kostić, Olivera",
year = "2014",
abstract = "Tokom aerodinamičkog projektovanja aviona, shodno njegovoj kategoriji i fazi razvoja projekta, potrebno je koristiti adekvatne proračunske metode i softverske alate. U slučaju lakih aviona, uobičajeno se koriste analitičke i semiempirijske metode u inicijalnoj fazi, kombinovane sa jednostavnim - neviskoznim CFD proračunskim modelima, dok se u kasnijim fazama obavljaju relativno kompleksne CFD analize sa uticajem viskoznosti. U današnje vreme se, u kategoriji lakih aviona, podrazumeva da savremeni proračunski alati za svaku od faza razvoja moraju biti adekvatno izabrani, tako da se njima dobijeni rezultati međusobno verifikuju i dopunjavaju. U radu su prikazane proračunske metode korišćene tokom aerodinamičke analize novog lakog aviona u različitim fazama njegovog razvoja i izvršeno je poređenje dobijenih rezultata, u cilju verifikacije ispunjenja navedenog uslova., During the evolution of an airplane aerodynamic design, proper calculation methods and software tools should be utilized, which correspond to the airplane category and project development level. In case of light aircraft, the general trend is the application of analytical and semiempirical methods at the initial stages, combined with simplified - inviscid CFD computational models, and fairly complex viscous CFD analyses at higher design levels. At the present stage of light aviation development, it is assumed that the contemporary design tools for each of those steps should be appropriate enough, so that they actually verify and additionally fine-tune each other's results. This paper describes the calculation tools and methods applied during the aerodynamic analyses of a new light aircraft at different development stages, and compares the results obtained by them, with the aim to verify and support the above statement, considering light aircraft aerodynamic design.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet, Beograd",
journal = "FME Transactions",
title = "Aerodinamička analiza lakog aviona u različitim razvojnim fazama projekta, Aerodynamic analysis of a light aircraft at different design stages",
pages = "105-94",
number = "2",
volume = "42",
doi = "10.5937/fmet1402094K"
}

Kostić, I., Stefanović, Z.,& Kostić, O.. (2014). Aerodinamička analiza lakog aviona u različitim razvojnim fazama projekta. in FME Transactions
Univerzitet u Beogradu - Mašinski fakultet, Beograd., 42(2), 94-105.
https://doi.org/10.5937/fmet1402094K

Kostić I, Stefanović Z, Kostić O. Aerodinamička analiza lakog aviona u različitim razvojnim fazama projekta. in FME Transactions. 2014;42(2):94-105.
doi:10.5937/fmet1402094K .

Kostić, Ivan, Stefanović, Zoran, Kostić, Olivera, "Aerodinamička analiza lakog aviona u različitim razvojnim fazama projekta" in FME Transactions, 42, no. 2 (2014):94-105,
https://doi.org/10.5937/fmet1402094K . .

TY  - JOUR
AU  - Kostić, Ivan
AU  - Stefanović, Zoran
AU  - Petrović, Zlatko
AU  - Kostić, Olivera
AU  - Essari, Abdulhakim
PY  - 2013
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1796
AB  - The paper is focused on the preliminary aerodynamic analyses of a new light aircraft in symmetrical flight configurations. Initial calculations have been done using a 3D vortex lattice method. Since this method is based on inviscid flow concept, the non-linear calibration diagrams for the effectiveness and circulation of control surfaces have been derived from wind tunnel test data of an existing airplane. These calibration functions have been interpolated for a new light aircraft geometry, and analyses of lift and moment coefficients with different flaps and elevator deflections have been performed. Deflected flaps and elevator generate local lift redistributions which contribute to the induced drag, even at angles of attack when the total airplane lift is zero, which has been successfully determined by the applied CFD model. Parasite drag components, omitted by CFD calculations, have been obtained using DVL and Datcom methods and superimposed with CFD results, giving complete new aircraft polars, which have been successfully applied in longitudinal stability and basic performance estimates.
PB  - Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek
T2  - Tehnički vjesnik
T1  - Hybrid approach in the initial aerodynamic, stability and performance calculations of a light airplane
EP  - 614
IS  - 4
SP  - 605
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1796
ER  - 

@article{
author = "Kostić, Ivan and Stefanović, Zoran and Petrović, Zlatko and Kostić, Olivera and Essari, Abdulhakim",
year = "2013",
abstract = "The paper is focused on the preliminary aerodynamic analyses of a new light aircraft in symmetrical flight configurations. Initial calculations have been done using a 3D vortex lattice method. Since this method is based on inviscid flow concept, the non-linear calibration diagrams for the effectiveness and circulation of control surfaces have been derived from wind tunnel test data of an existing airplane. These calibration functions have been interpolated for a new light aircraft geometry, and analyses of lift and moment coefficients with different flaps and elevator deflections have been performed. Deflected flaps and elevator generate local lift redistributions which contribute to the induced drag, even at angles of attack when the total airplane lift is zero, which has been successfully determined by the applied CFD model. Parasite drag components, omitted by CFD calculations, have been obtained using DVL and Datcom methods and superimposed with CFD results, giving complete new aircraft polars, which have been successfully applied in longitudinal stability and basic performance estimates.",
publisher = "Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek",
journal = "Tehnički vjesnik",
title = "Hybrid approach in the initial aerodynamic, stability and performance calculations of a light airplane",
pages = "614-605",
number = "4",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1796"
}

Kostić, I., Stefanović, Z., Petrović, Z., Kostić, O.,& Essari, A.. (2013). Hybrid approach in the initial aerodynamic, stability and performance calculations of a light airplane. in Tehnički vjesnik
Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek., 20(4), 605-614.
https://hdl.handle.net/21.15107/rcub_machinery_1796

Kostić I, Stefanović Z, Petrović Z, Kostić O, Essari A. Hybrid approach in the initial aerodynamic, stability and performance calculations of a light airplane. in Tehnički vjesnik. 2013;20(4):605-614.
https://hdl.handle.net/21.15107/rcub_machinery_1796 .

Kostić, Ivan, Stefanović, Zoran, Petrović, Zlatko, Kostić, Olivera, Essari, Abdulhakim, "Hybrid approach in the initial aerodynamic, stability and performance calculations of a light airplane" in Tehnički vjesnik, 20, no. 4 (2013):605-614,
https://hdl.handle.net/21.15107/rcub_machinery_1796 .

TY  - JOUR
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
AU  - Kostić, Olivera
PY  - 2012
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1598
AB  - In the preliminary aerodynamic aircraft design, optimum calculation methods should be used, which enable engineers to perform a vast number of test runs in a reasonably short time. Such tools should not only be fairly simple but also reliable. In the first part, this paper briefly presents aerodynamic analyses performed by a 3D vortex lattice method (VLM), with an aim to verify its capabilities to give results that coincide well with the experimental data of an existing airplane. Since this computational model is based on inviscid flow concept, effectiveness of control surfaces and flaps are inherently overestimated. In order to compensate for the omitted boundary layer influence, a set of calibration diagrams for effectiveness and circulation influence has been successfully derived and good agreements with wind tunnel test data have been achieved. After several necessary adjustments, calibration functions have been applied to VLM analysis within a new light aircraft conceptual study. Those results have been compared with results obtained by well known Datcom method and verygood agreements have been achieved, proving that VLM computations with properly defined calibration functions can be both efficient and reliable tools in preliminary aerodynamic design.
T2  - Engineering Review
T1  - Efficient evaluation of preliminary aerodynamic characteristics of light trainer aircraft
EP  - 56
IS  - 1
SP  - 49
VL  - 32
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1598
ER  - 

@article{
author = "Stefanović, Zoran and Kostić, Ivan and Kostić, Olivera",
year = "2012",
abstract = "In the preliminary aerodynamic aircraft design, optimum calculation methods should be used, which enable engineers to perform a vast number of test runs in a reasonably short time. Such tools should not only be fairly simple but also reliable. In the first part, this paper briefly presents aerodynamic analyses performed by a 3D vortex lattice method (VLM), with an aim to verify its capabilities to give results that coincide well with the experimental data of an existing airplane. Since this computational model is based on inviscid flow concept, effectiveness of control surfaces and flaps are inherently overestimated. In order to compensate for the omitted boundary layer influence, a set of calibration diagrams for effectiveness and circulation influence has been successfully derived and good agreements with wind tunnel test data have been achieved. After several necessary adjustments, calibration functions have been applied to VLM analysis within a new light aircraft conceptual study. Those results have been compared with results obtained by well known Datcom method and verygood agreements have been achieved, proving that VLM computations with properly defined calibration functions can be both efficient and reliable tools in preliminary aerodynamic design.",
journal = "Engineering Review",
title = "Efficient evaluation of preliminary aerodynamic characteristics of light trainer aircraft",
pages = "56-49",
number = "1",
volume = "32",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1598"
}

Stefanović, Z., Kostić, I.,& Kostić, O.. (2012). Efficient evaluation of preliminary aerodynamic characteristics of light trainer aircraft. in Engineering Review, 32(1), 49-56.
https://hdl.handle.net/21.15107/rcub_machinery_1598

Stefanović Z, Kostić I, Kostić O. Efficient evaluation of preliminary aerodynamic characteristics of light trainer aircraft. in Engineering Review. 2012;32(1):49-56.
https://hdl.handle.net/21.15107/rcub_machinery_1598 .

Stefanović, Zoran, Kostić, Ivan, Kostić, Olivera, "Efficient evaluation of preliminary aerodynamic characteristics of light trainer aircraft" in Engineering Review, 32, no. 1 (2012):49-56,
https://hdl.handle.net/21.15107/rcub_machinery_1598 .

TY  - CONF
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
AU  - Kostić, Olivera
PY  - 2012
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1447
AB  - The paper is confined to the preliminary aerodynamic analyses of a new light aircraft with different combinations of flaps and elevator deflections, which correspond to the symmetrical flight conditions. Initial calculations have been performed using a 3D vortex lattice method. Since the applied computational model is based on inviscid flow concept, the non-linear calibration diagrams for the effectiveness of control surfaces and circulation influence have been derived from wind tunnel test data for an existing airplane. Then the calibration functions have been interpolated for a new light aircraft, and a wide scope of analyses for lift and moment coefficients with different flaps and elevator deflections has been performed Of special importance was the determination of lift-induced drag polars. Namely, deflected flaps and elevator generate local lift distributions which contribute to the induced drag, even at angles of attack when the total airplane 10 is zero, which has been successfully determined by the applied CFD model. Parasite drag components, omitted by CFD calculations, have been estimated using DVL, Datcom and Douglas methods and superimposed with the induced drag results, giving complete diagrams for the new aircraft in different symmetric flight configurations.
PB  - Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad
C3  - Machine and Industrial Design in Mechanical Engineering, Seventh International Symposium, Kod 2012
T1  - Primary aerodynamic analyses of a new light aircraft in symmetrical flight configurations
EP  - 104
SP  - 97
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1447
ER  - 

@conference{
author = "Stefanović, Zoran and Kostić, Ivan and Kostić, Olivera",
year = "2012",
abstract = "The paper is confined to the preliminary aerodynamic analyses of a new light aircraft with different combinations of flaps and elevator deflections, which correspond to the symmetrical flight conditions. Initial calculations have been performed using a 3D vortex lattice method. Since the applied computational model is based on inviscid flow concept, the non-linear calibration diagrams for the effectiveness of control surfaces and circulation influence have been derived from wind tunnel test data for an existing airplane. Then the calibration functions have been interpolated for a new light aircraft, and a wide scope of analyses for lift and moment coefficients with different flaps and elevator deflections has been performed Of special importance was the determination of lift-induced drag polars. Namely, deflected flaps and elevator generate local lift distributions which contribute to the induced drag, even at angles of attack when the total airplane 10 is zero, which has been successfully determined by the applied CFD model. Parasite drag components, omitted by CFD calculations, have been estimated using DVL, Datcom and Douglas methods and superimposed with the induced drag results, giving complete diagrams for the new aircraft in different symmetric flight configurations.",
publisher = "Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad",
journal = "Machine and Industrial Design in Mechanical Engineering, Seventh International Symposium, Kod 2012",
title = "Primary aerodynamic analyses of a new light aircraft in symmetrical flight configurations",
pages = "104-97",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1447"
}

Stefanović, Z., Kostić, I.,& Kostić, O.. (2012). Primary aerodynamic analyses of a new light aircraft in symmetrical flight configurations. in Machine and Industrial Design in Mechanical Engineering, Seventh International Symposium, Kod 2012
Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad., 97-104.
https://hdl.handle.net/21.15107/rcub_machinery_1447

Stefanović Z, Kostić I, Kostić O. Primary aerodynamic analyses of a new light aircraft in symmetrical flight configurations. in Machine and Industrial Design in Mechanical Engineering, Seventh International Symposium, Kod 2012. 2012;:97-104.
https://hdl.handle.net/21.15107/rcub_machinery_1447 .

Stefanović, Zoran, Kostić, Ivan, Kostić, Olivera, "Primary aerodynamic analyses of a new light aircraft in symmetrical flight configurations" in Machine and Industrial Design in Mechanical Engineering, Seventh International Symposium, Kod 2012 (2012):97-104,
https://hdl.handle.net/21.15107/rcub_machinery_1447 .

TY  - JOUR
AU  - Benisa, Muamar
AU  - Babić, Bojan
AU  - Grbović, Aleksandar
AU  - Stefanović, Zoran
PY  - 2012
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1573
AB  - The conventional way to develop press-formed metallic components requires a burdensome trial-and-error process for setting-up the technology, whose success depends largely on the operator's skill and experience. The finite element (FE) simulations of a sheet-metal-forming process help a manufacturing engineer to design a forming process by shifting the costly press-shop try-outs to the computer-aided design environment. Numerical simulations of a manufacturing process, such as rubber-pad forming, have been introduced in order to avoid the trial-and-error procedure and shorten the development phases when tight times-to-market are demanded. The main aim of the investigation presented in this paper was to develop a numerical model that would be able to successfully simulate a rubber-pad forming process. The finite-element method was used for blank- and rubber-behavior predictions during the process. The study was concerned with a simulation and investigation of significant parameters (such as forming force and stress, and strain distribution in a blank) associated with the rubber-pad forming process and the capabilities of this process regarding the manufacturing of aircraft wing ribs. The simulation and investigation carried out identified the stress and strain distribution in a blank as well as the forming force. Experimental analyses of a rib with a lightening hole showed a good correlation between FE simulations and experimental results.
PB  - Institute of Metals and Technology
T2  - Materiali in Tehnologije
T1  - Computer-aided modeling of the rubber-pad forming process
EP  - 510
IS  - 5
SP  - 503
VL  - 46
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1573
ER  - 

@article{
author = "Benisa, Muamar and Babić, Bojan and Grbović, Aleksandar and Stefanović, Zoran",
year = "2012",
abstract = "The conventional way to develop press-formed metallic components requires a burdensome trial-and-error process for setting-up the technology, whose success depends largely on the operator's skill and experience. The finite element (FE) simulations of a sheet-metal-forming process help a manufacturing engineer to design a forming process by shifting the costly press-shop try-outs to the computer-aided design environment. Numerical simulations of a manufacturing process, such as rubber-pad forming, have been introduced in order to avoid the trial-and-error procedure and shorten the development phases when tight times-to-market are demanded. The main aim of the investigation presented in this paper was to develop a numerical model that would be able to successfully simulate a rubber-pad forming process. The finite-element method was used for blank- and rubber-behavior predictions during the process. The study was concerned with a simulation and investigation of significant parameters (such as forming force and stress, and strain distribution in a blank) associated with the rubber-pad forming process and the capabilities of this process regarding the manufacturing of aircraft wing ribs. The simulation and investigation carried out identified the stress and strain distribution in a blank as well as the forming force. Experimental analyses of a rib with a lightening hole showed a good correlation between FE simulations and experimental results.",
publisher = "Institute of Metals and Technology",
journal = "Materiali in Tehnologije",
title = "Computer-aided modeling of the rubber-pad forming process",
pages = "510-503",
number = "5",
volume = "46",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1573"
}

Benisa, M., Babić, B., Grbović, A.,& Stefanović, Z.. (2012). Computer-aided modeling of the rubber-pad forming process. in Materiali in Tehnologije
Institute of Metals and Technology., 46(5), 503-510.
https://hdl.handle.net/21.15107/rcub_machinery_1573

Benisa M, Babić B, Grbović A, Stefanović Z. Computer-aided modeling of the rubber-pad forming process. in Materiali in Tehnologije. 2012;46(5):503-510.
https://hdl.handle.net/21.15107/rcub_machinery_1573 .

Benisa, Muamar, Babić, Bojan, Grbović, Aleksandar, Stefanović, Zoran, "Computer-aided modeling of the rubber-pad forming process" in Materiali in Tehnologije, 46, no. 5 (2012):503-510,
https://hdl.handle.net/21.15107/rcub_machinery_1573 .

TY  - JOUR
AU  - Tomić, Radoljub
AU  - Sedmak, Aleksandar
AU  - Ćatić, Dobrivoje M.
AU  - Miloš, Marko
AU  - Stefanović, Zoran
PY  - 2011
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1175
AB  - Paper presents stress calculation in the stationary temperature domain for a hybrid structure with standard epoxy-carbon fiber composite and metallic part, showing different thermal behavior. The thermal stress analysis is based on the finite element method. A sample problem involving such a composite plate and metallic part of structure or mould at two different temperature levels, corresponding to curing process (co-curing) and operating temperatures, respectively, is calculated and discussed. The specific properties of composite are emphasized particularly for thermal coefficients, especially if the shear coefficient is different than zero, causing completely different behavior compared to isotropic materials.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Thermal stress analysis of a fiber-epoxy composite material
EP  - 563
IS  - 2
SP  - 559
VL  - 15
DO  - 10.2298/TSCI1102559T
ER  - 

@article{
author = "Tomić, Radoljub and Sedmak, Aleksandar and Ćatić, Dobrivoje M. and Miloš, Marko and Stefanović, Zoran",
year = "2011",
abstract = "Paper presents stress calculation in the stationary temperature domain for a hybrid structure with standard epoxy-carbon fiber composite and metallic part, showing different thermal behavior. The thermal stress analysis is based on the finite element method. A sample problem involving such a composite plate and metallic part of structure or mould at two different temperature levels, corresponding to curing process (co-curing) and operating temperatures, respectively, is calculated and discussed. The specific properties of composite are emphasized particularly for thermal coefficients, especially if the shear coefficient is different than zero, causing completely different behavior compared to isotropic materials.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Thermal stress analysis of a fiber-epoxy composite material",
pages = "563-559",
number = "2",
volume = "15",
doi = "10.2298/TSCI1102559T"
}

Tomić, R., Sedmak, A., Ćatić, D. M., Miloš, M.,& Stefanović, Z.. (2011). Thermal stress analysis of a fiber-epoxy composite material. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 15(2), 559-563.
https://doi.org/10.2298/TSCI1102559T

Tomić R, Sedmak A, Ćatić DM, Miloš M, Stefanović Z. Thermal stress analysis of a fiber-epoxy composite material. in Thermal Science. 2011;15(2):559-563.
doi:10.2298/TSCI1102559T .

Tomić, Radoljub, Sedmak, Aleksandar, Ćatić, Dobrivoje M., Miloš, Marko, Stefanović, Zoran, "Thermal stress analysis of a fiber-epoxy composite material" in Thermal Science, 15, no. 2 (2011):559-563,
https://doi.org/10.2298/TSCI1102559T . .

TY  - JOUR
AU  - Stefanović, Zoran
AU  - Miloš, Marko
AU  - Todić, Ivana
AU  - Pavlović, M.
PY  - 2011
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1331
AB  - This paper introduces a new physical model of the gas flow through the 2D nozzle with the tilted obstacle in exit section. Experimental research on the 2D full span model in the supersonic indraft tunnel, which includes over three hundred tunnel runs, are presented. Variable geometric parameters were: nozzle shadow area, obstacle-nozzle wall angle, obstacle-nozzle gap and nozzle area ratio. In its conclusion, the paper discusses results and presents some suggestions for the future research.
PB  - Croation Union of Mech. Engineers and Naval Architects
T2  - Strojarstvo
T1  - Investigation of the pressure distribution in a 2D rocket nozzle with a mechanical system for thrust vector control (TVC)
EP  - 292
IS  - 4
SP  - 287
VL  - 53
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1331
ER  - 

@article{
author = "Stefanović, Zoran and Miloš, Marko and Todić, Ivana and Pavlović, M.",
year = "2011",
abstract = "This paper introduces a new physical model of the gas flow through the 2D nozzle with the tilted obstacle in exit section. Experimental research on the 2D full span model in the supersonic indraft tunnel, which includes over three hundred tunnel runs, are presented. Variable geometric parameters were: nozzle shadow area, obstacle-nozzle wall angle, obstacle-nozzle gap and nozzle area ratio. In its conclusion, the paper discusses results and presents some suggestions for the future research.",
publisher = "Croation Union of Mech. Engineers and Naval Architects",
journal = "Strojarstvo",
title = "Investigation of the pressure distribution in a 2D rocket nozzle with a mechanical system for thrust vector control (TVC)",
pages = "292-287",
number = "4",
volume = "53",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1331"
}

Stefanović, Z., Miloš, M., Todić, I.,& Pavlović, M.. (2011). Investigation of the pressure distribution in a 2D rocket nozzle with a mechanical system for thrust vector control (TVC). in Strojarstvo
Croation Union of Mech. Engineers and Naval Architects., 53(4), 287-292.
https://hdl.handle.net/21.15107/rcub_machinery_1331

Stefanović Z, Miloš M, Todić I, Pavlović M. Investigation of the pressure distribution in a 2D rocket nozzle with a mechanical system for thrust vector control (TVC). in Strojarstvo. 2011;53(4):287-292.
https://hdl.handle.net/21.15107/rcub_machinery_1331 .

Stefanović, Zoran, Miloš, Marko, Todić, Ivana, Pavlović, M., "Investigation of the pressure distribution in a 2D rocket nozzle with a mechanical system for thrust vector control (TVC)" in Strojarstvo, 53, no. 4 (2011):287-292,
https://hdl.handle.net/21.15107/rcub_machinery_1331 .

TY  - JOUR
AU  - Khan, Muhammad Ashraf
AU  - Todić, Ivana
AU  - Miloš, Marko
AU  - Stefanović, Zoran
AU  - Blagojević, Đorđe
PY  - 2010
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/994
AB  - The paper mainly focuses two major areas of electromechanical actuator system composed of power screw, spur gear train and Brushless DC Servo Motor. First it describes control of electromechanical actuator system with three level of current controller which is composed of power amplifier, DSP module and interfacing circuitry. The non-linear model of the three level controllers developed in SIMULINK environment is presented. A second point which was included in this study is the comparison of two control strategies i.e. three level controller and PWM current controller. The main outcomes of the study is that three level controller is simple in construction and much more stable. This is much suitable for higher reduction systems, short missions and low power density actuators; however it has few limitation that make it unsuitable for applications such as high power density, long missions and direct drive system.
PB  - Croation Union of Mech. Engineers and Naval Architects
T2  - Strojarstvo
T1  - Control of Electro-Mechanical Actuator for Aerospace Applications
EP  - 312
IS  - 3
SP  - 303
VL  - 52
UR  - https://hdl.handle.net/21.15107/rcub_machinery_994
ER  - 

@article{
author = "Khan, Muhammad Ashraf and Todić, Ivana and Miloš, Marko and Stefanović, Zoran and Blagojević, Đorđe",
year = "2010",
abstract = "The paper mainly focuses two major areas of electromechanical actuator system composed of power screw, spur gear train and Brushless DC Servo Motor. First it describes control of electromechanical actuator system with three level of current controller which is composed of power amplifier, DSP module and interfacing circuitry. The non-linear model of the three level controllers developed in SIMULINK environment is presented. A second point which was included in this study is the comparison of two control strategies i.e. three level controller and PWM current controller. The main outcomes of the study is that three level controller is simple in construction and much more stable. This is much suitable for higher reduction systems, short missions and low power density actuators; however it has few limitation that make it unsuitable for applications such as high power density, long missions and direct drive system.",
publisher = "Croation Union of Mech. Engineers and Naval Architects",
journal = "Strojarstvo",
title = "Control of Electro-Mechanical Actuator for Aerospace Applications",
pages = "312-303",
number = "3",
volume = "52",
url = "https://hdl.handle.net/21.15107/rcub_machinery_994"
}

Khan, M. A., Todić, I., Miloš, M., Stefanović, Z.,& Blagojević, Đ.. (2010). Control of Electro-Mechanical Actuator for Aerospace Applications. in Strojarstvo
Croation Union of Mech. Engineers and Naval Architects., 52(3), 303-312.
https://hdl.handle.net/21.15107/rcub_machinery_994

Khan MA, Todić I, Miloš M, Stefanović Z, Blagojević Đ. Control of Electro-Mechanical Actuator for Aerospace Applications. in Strojarstvo. 2010;52(3):303-312.
https://hdl.handle.net/21.15107/rcub_machinery_994 .

Khan, Muhammad Ashraf, Todić, Ivana, Miloš, Marko, Stefanović, Zoran, Blagojević, Đorđe, "Control of Electro-Mechanical Actuator for Aerospace Applications" in Strojarstvo, 52, no. 3 (2010):303-312,
https://hdl.handle.net/21.15107/rcub_machinery_994 .

TY  - JOUR
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
PY  - 2010
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/991
AB  - High lift-to-drag ratios of the contemporary sailplanes make them the most energy efficient flying vehicles. On the other hand, this capability may become their serious disadvantage during the landing, if their aerodynamic deceleration devices become inoperable in flight. Not being able to dissipate the excess energy quickly when close to the ground, they may fly over the available landing ground and finish up in front of the obstacles, with still too much energy to land and not enough to fly over them. Beside the sideslipping flight in final, where energy is dissipated through the increased sideforce drag, another solution to this problem has been offered in a number of papers. By numerical analyses they have shown that landing distance in such cases could be minimized using rather complex oscillating flight paths in vertical plane. Although relevant distance reductions could be achieved through them, performing such paths in practice would require exceptional piloting skills. Instead of that, in this paper much simpler approach profiles have been analyzed, based on two types of cosine speed variations with constant periods and amplitudes, which could be flown by pilots of average flying experience. After establishing a quick convergence algorithm, numerical solutions for several typical cases, belonging to two general speed variation types, have been presented. The same initial and terminal reference energy states have been used. Although the distance reductions are smaller than obtained by distance-minimizing techniques, operational simplicity of presented techniques and some specific advantages prove them valuable within this categoiy of problems.
T2  - Strojniski Vestnik/Journal of Mechanical Engineering
T1  - Analysis of the Sailplane Final Approaches Performed by Cosine-Law Speed Variations
EP  - 446
IS  - 7-8
SP  - 436
VL  - 56
UR  - https://hdl.handle.net/21.15107/rcub_machinery_991
ER  - 

@article{
author = "Stefanović, Zoran and Kostić, Ivan",
year = "2010",
abstract = "High lift-to-drag ratios of the contemporary sailplanes make them the most energy efficient flying vehicles. On the other hand, this capability may become their serious disadvantage during the landing, if their aerodynamic deceleration devices become inoperable in flight. Not being able to dissipate the excess energy quickly when close to the ground, they may fly over the available landing ground and finish up in front of the obstacles, with still too much energy to land and not enough to fly over them. Beside the sideslipping flight in final, where energy is dissipated through the increased sideforce drag, another solution to this problem has been offered in a number of papers. By numerical analyses they have shown that landing distance in such cases could be minimized using rather complex oscillating flight paths in vertical plane. Although relevant distance reductions could be achieved through them, performing such paths in practice would require exceptional piloting skills. Instead of that, in this paper much simpler approach profiles have been analyzed, based on two types of cosine speed variations with constant periods and amplitudes, which could be flown by pilots of average flying experience. After establishing a quick convergence algorithm, numerical solutions for several typical cases, belonging to two general speed variation types, have been presented. The same initial and terminal reference energy states have been used. Although the distance reductions are smaller than obtained by distance-minimizing techniques, operational simplicity of presented techniques and some specific advantages prove them valuable within this categoiy of problems.",
journal = "Strojniski Vestnik/Journal of Mechanical Engineering",
title = "Analysis of the Sailplane Final Approaches Performed by Cosine-Law Speed Variations",
pages = "446-436",
number = "7-8",
volume = "56",
url = "https://hdl.handle.net/21.15107/rcub_machinery_991"
}

Stefanović, Z.,& Kostić, I.. (2010). Analysis of the Sailplane Final Approaches Performed by Cosine-Law Speed Variations. in Strojniski Vestnik/Journal of Mechanical Engineering, 56(7-8), 436-446.
https://hdl.handle.net/21.15107/rcub_machinery_991

Stefanović Z, Kostić I. Analysis of the Sailplane Final Approaches Performed by Cosine-Law Speed Variations. in Strojniski Vestnik/Journal of Mechanical Engineering. 2010;56(7-8):436-446.
https://hdl.handle.net/21.15107/rcub_machinery_991 .

Stefanović, Zoran, Kostić, Ivan, "Analysis of the Sailplane Final Approaches Performed by Cosine-Law Speed Variations" in Strojniski Vestnik/Journal of Mechanical Engineering, 56, no. 7-8 (2010):436-446,
https://hdl.handle.net/21.15107/rcub_machinery_991 .

TY  - CONF
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
PY  - 2010
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1122
AB  - In initial stages of aircraft aerodynamic design, it is common practice to apply fairly simple but reliable computer packages, that enable engineers to perform a large number of test runs in a reasonably short time. This paper is mainly focused on the tests done by such software, based on 3D vortex-lattice method, with an aim to verb its capabilities to give results that properly coincide with the existing airplane's data. For software reliability tests, the popular domestic Utva-75 light aircraft has been selected, for which a wide scope of wind tunnel test results exist. Since the applied computational model is based on inviscid flow concept, effectiveness of the flaps and control surfaces, deflected to angles larger than 5 degrees, are inherently overestimated. In order to compensate for the omitted boundary layer influence and separation effects, a set of calibration options has been properly applied, the non-linear calibration diagrams for their effectiveness and circulation influence have been derived and very good agreements with wind tunnel data have been achieved. The actual aim of defining software calibration functions is to enable efficient prediction and optimization of the large number of aerodynamic characteristics for a new airplane of the same category, during the first stages of its conceptual analysis.
PB  - Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad
C3  - Sixth International Symposium About Forming and Design in Mechanical Engineering
T1  - A vortex lattice method application in aerodynamic analysis and design of light aircraft
EP  - 92
SP  - 85
UR  - https://hdl.handle.net/21.15107/rcub_machinery_1122
ER  - 

@conference{
author = "Stefanović, Zoran and Kostić, Ivan",
year = "2010",
abstract = "In initial stages of aircraft aerodynamic design, it is common practice to apply fairly simple but reliable computer packages, that enable engineers to perform a large number of test runs in a reasonably short time. This paper is mainly focused on the tests done by such software, based on 3D vortex-lattice method, with an aim to verb its capabilities to give results that properly coincide with the existing airplane's data. For software reliability tests, the popular domestic Utva-75 light aircraft has been selected, for which a wide scope of wind tunnel test results exist. Since the applied computational model is based on inviscid flow concept, effectiveness of the flaps and control surfaces, deflected to angles larger than 5 degrees, are inherently overestimated. In order to compensate for the omitted boundary layer influence and separation effects, a set of calibration options has been properly applied, the non-linear calibration diagrams for their effectiveness and circulation influence have been derived and very good agreements with wind tunnel data have been achieved. The actual aim of defining software calibration functions is to enable efficient prediction and optimization of the large number of aerodynamic characteristics for a new airplane of the same category, during the first stages of its conceptual analysis.",
publisher = "Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad",
journal = "Sixth International Symposium About Forming and Design in Mechanical Engineering",
title = "A vortex lattice method application in aerodynamic analysis and design of light aircraft",
pages = "92-85",
url = "https://hdl.handle.net/21.15107/rcub_machinery_1122"
}

Stefanović, Z.,& Kostić, I.. (2010). A vortex lattice method application in aerodynamic analysis and design of light aircraft. in Sixth International Symposium About Forming and Design in Mechanical Engineering
Univ Novi Sad, Fac Tech Sci, Adeko, Novi Sad., 85-92.
https://hdl.handle.net/21.15107/rcub_machinery_1122

Stefanović Z, Kostić I. A vortex lattice method application in aerodynamic analysis and design of light aircraft. in Sixth International Symposium About Forming and Design in Mechanical Engineering. 2010;:85-92.
https://hdl.handle.net/21.15107/rcub_machinery_1122 .

Stefanović, Zoran, Kostić, Ivan, "A vortex lattice method application in aerodynamic analysis and design of light aircraft" in Sixth International Symposium About Forming and Design in Mechanical Engineering (2010):85-92,
https://hdl.handle.net/21.15107/rcub_machinery_1122 .

TY  - JOUR
AU  - Stefanović, Zoran
AU  - Kostić, Ivan
PY  - 2007
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/722
AB  - Ukoliko iz bilo kog tehničkog razloga vazdušne kočnice prestanu da funkcionišu tokom leta, najkritičnija faza u proceduri sletanja jedrilice je finalni prilaz. Pored leta sa bočnim klizanjem, kada se disipacija energije vrši kroz povećanje bočne sile otpora, drugo moguće rešenje ovog problema je ponuđeno u literaturi, gde je pokazano da se dužina prilaza može minimizirati primenom složenih oscilatornih putanja leta. Međutim, let po takvim putanjama zahteva izuzetno letačko umeće. Nasuprot tome, u ovom radu izvršena je analiza jednostavnijih prilaznih putanja, baziranih na harmonijskim promenama brzine, koje je mnogo lakše operativno reprodukovati u letu. U radu je prikazan proračunski algoritam koji omogućava brzu konvergenciju rešenja i analizirana su numerička rešenja za nekoliko tipičnih slučajeva. Kao primer korišćeni su podaci za jedrilicu Vuk-T. Dobijeni rezultati pokazuju nešto manja skraćenja putanja, ali jednostavnost primene u praksi i veća bezbednost predloženih tehnika letenja čini ih korisnim rešenjima u slučaju pomenutih problema.
AB  - When for any technical reason spoilers become inoperable in flight, the most critical phase of a sailplane landing procedure is final approach. Besides the sideslipping flight possibility, where energy is dissipated through the increased sideforce drag, another solution for this problem has been offered in literature, showing that the landing distance could be minimized using rather complex oscillating flight paths. The problem is that performing such paths in practice would require exceptional piloting skills. Instead of that, in this paper much simpler approach profiles have been analyzed, based on the simple harmonic speed variations, which could much easier be reproduced in practice. After establishing a quick convergence algorithm, numerical solutions for several typical cases, taking the Vuk-T sailplane as an example, have been presented. Although distance reductions are generally smaller than obtained by distance-minimizing techniques, their operational simplicity and higher safety prove them as valuable solutions for this kind of problems.
PB  - Univerzitet u Beogradu - Mašinski fakultet, Beograd
T2  - FME Transactions
T1  - Uticaj prostih harmonijskih promena brzine ha oblik i dužinu prilazne putanje jedrilice Vuk-T
T1  - Influence of simple harmonic speed variations on the Vuk-T sailplane approach paths and distances
EP  - 75
IS  - 2
SP  - 69
VL  - 35
UR  - https://hdl.handle.net/21.15107/rcub_machinery_722
ER  - 

@article{
author = "Stefanović, Zoran and Kostić, Ivan",
year = "2007",
abstract = "Ukoliko iz bilo kog tehničkog razloga vazdušne kočnice prestanu da funkcionišu tokom leta, najkritičnija faza u proceduri sletanja jedrilice je finalni prilaz. Pored leta sa bočnim klizanjem, kada se disipacija energije vrši kroz povećanje bočne sile otpora, drugo moguće rešenje ovog problema je ponuđeno u literaturi, gde je pokazano da se dužina prilaza može minimizirati primenom složenih oscilatornih putanja leta. Međutim, let po takvim putanjama zahteva izuzetno letačko umeće. Nasuprot tome, u ovom radu izvršena je analiza jednostavnijih prilaznih putanja, baziranih na harmonijskim promenama brzine, koje je mnogo lakše operativno reprodukovati u letu. U radu je prikazan proračunski algoritam koji omogućava brzu konvergenciju rešenja i analizirana su numerička rešenja za nekoliko tipičnih slučajeva. Kao primer korišćeni su podaci za jedrilicu Vuk-T. Dobijeni rezultati pokazuju nešto manja skraćenja putanja, ali jednostavnost primene u praksi i veća bezbednost predloženih tehnika letenja čini ih korisnim rešenjima u slučaju pomenutih problema., When for any technical reason spoilers become inoperable in flight, the most critical phase of a sailplane landing procedure is final approach. Besides the sideslipping flight possibility, where energy is dissipated through the increased sideforce drag, another solution for this problem has been offered in literature, showing that the landing distance could be minimized using rather complex oscillating flight paths. The problem is that performing such paths in practice would require exceptional piloting skills. Instead of that, in this paper much simpler approach profiles have been analyzed, based on the simple harmonic speed variations, which could much easier be reproduced in practice. After establishing a quick convergence algorithm, numerical solutions for several typical cases, taking the Vuk-T sailplane as an example, have been presented. Although distance reductions are generally smaller than obtained by distance-minimizing techniques, their operational simplicity and higher safety prove them as valuable solutions for this kind of problems.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet, Beograd",
journal = "FME Transactions",
title = "Uticaj prostih harmonijskih promena brzine ha oblik i dužinu prilazne putanje jedrilice Vuk-T, Influence of simple harmonic speed variations on the Vuk-T sailplane approach paths and distances",
pages = "75-69",
number = "2",
volume = "35",
url = "https://hdl.handle.net/21.15107/rcub_machinery_722"
}

Stefanović, Z.,& Kostić, I.. (2007). Uticaj prostih harmonijskih promena brzine ha oblik i dužinu prilazne putanje jedrilice Vuk-T. in FME Transactions
Univerzitet u Beogradu - Mašinski fakultet, Beograd., 35(2), 69-75.
https://hdl.handle.net/21.15107/rcub_machinery_722

Stefanović Z, Kostić I. Uticaj prostih harmonijskih promena brzine ha oblik i dužinu prilazne putanje jedrilice Vuk-T. in FME Transactions. 2007;35(2):69-75.
https://hdl.handle.net/21.15107/rcub_machinery_722 .

Stefanović, Zoran, Kostić, Ivan, "Uticaj prostih harmonijskih promena brzine ha oblik i dužinu prilazne putanje jedrilice Vuk-T" in FME Transactions, 35, no. 2 (2007):69-75,
https://hdl.handle.net/21.15107/rcub_machinery_722 .