TY  - CONF
AU  - Svorcan, Jelena
AU  - Kovačević, Aleksandar
AU  - Popović, Lazar
AU  - Simonović, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7073
PB  - Springer
PB  - SARES
C3  - Solutions for Maintenance Repair and Overhaul, Proceedings of the International Symposium on Aviation Technology, MRO, and Operations 2021
T1  - Sizing and Performance Analysis of a Single-Seat Tandem Helicopter
EP  - 227
SP  - 219
DO  - 10.1007/978-3-031-38446-2
ER  - 

@conference{
author = "Svorcan, Jelena and Kovačević, Aleksandar and Popović, Lazar and Simonović, Aleksandar",
year = "2023",
publisher = "Springer, SARES",
journal = "Solutions for Maintenance Repair and Overhaul, Proceedings of the International Symposium on Aviation Technology, MRO, and Operations 2021",
title = "Sizing and Performance Analysis of a Single-Seat Tandem Helicopter",
pages = "227-219",
doi = "10.1007/978-3-031-38446-2"
}

Svorcan, J., Kovačević, A., Popović, L.,& Simonović, A.. (2023). Sizing and Performance Analysis of a Single-Seat Tandem Helicopter. in Solutions for Maintenance Repair and Overhaul, Proceedings of the International Symposium on Aviation Technology, MRO, and Operations 2021
Springer., 219-227.
https://doi.org/10.1007/978-3-031-38446-2

Svorcan J, Kovačević A, Popović L, Simonović A. Sizing and Performance Analysis of a Single-Seat Tandem Helicopter. in Solutions for Maintenance Repair and Overhaul, Proceedings of the International Symposium on Aviation Technology, MRO, and Operations 2021. 2023;:219-227.
doi:10.1007/978-3-031-38446-2 .

Svorcan, Jelena, Kovačević, Aleksandar, Popović, Lazar, Simonović, Aleksandar, "Sizing and Performance Analysis of a Single-Seat Tandem Helicopter" in Solutions for Maintenance Repair and Overhaul, Proceedings of the International Symposium on Aviation Technology, MRO, and Operations 2021 (2023):219-227,
https://doi.org/10.1007/978-3-031-38446-2 . .

TY  - JOUR
AU  - Svorcan, Jelena
AU  - Kovacević, Aleksandar
AU  - Popović, Lazar
AU  - Simonović, Aleksandar
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3718
AB  - The paper presents a starting, but necessary comparative study between two diverse designs of single-seat tandem helicopter configuration, piston-propelled vs. electrically-driven. Both possibilities have their pros and cons, and need to be considered in detail, with respect to the initial requirements. In this investigation, the primary design objectives include 100 kg of payload as well as satisfactory performances in both hover and progressive flight. The comparison is conducted through the initial sizing procedures that enabled the estimation of takeoff mass (along with its main contributors), but also characteristic speeds, flight limits and basic helicopter performances. Used models and assumptions are explained in the paper. In the beginning, some essential advantages of tandem configuration helicopters are mentioned and accentuated. Also, future trends in electric aviation are considered. After that, total mass is decomposed into several main components and rotor dimensioning is performed. By assuming sufficient available power, it is possible to estimate the basic helicopter performances in both axisymmetric and progressive flight. Obtained results are presented graphically and numerically. In the end, some conclusions and recommendations for further research are given. For the time being, piston-propelled single-seat tandem helicopter can achieve better numerical results.
PB  - Inderscience Enterprises Ltd, Geneva
T2  - International Journal of Sustainable Aviation
T1  - Comparative study of piston vs. electric single-seat tandem helicopter
EP  - 14
IS  - 1
SP  - 1
VL  - 8
DO  - 10.1504/IJSA.2022.120614
ER  - 

@article{
author = "Svorcan, Jelena and Kovacević, Aleksandar and Popović, Lazar and Simonović, Aleksandar",
year = "2022",
abstract = "The paper presents a starting, but necessary comparative study between two diverse designs of single-seat tandem helicopter configuration, piston-propelled vs. electrically-driven. Both possibilities have their pros and cons, and need to be considered in detail, with respect to the initial requirements. In this investigation, the primary design objectives include 100 kg of payload as well as satisfactory performances in both hover and progressive flight. The comparison is conducted through the initial sizing procedures that enabled the estimation of takeoff mass (along with its main contributors), but also characteristic speeds, flight limits and basic helicopter performances. Used models and assumptions are explained in the paper. In the beginning, some essential advantages of tandem configuration helicopters are mentioned and accentuated. Also, future trends in electric aviation are considered. After that, total mass is decomposed into several main components and rotor dimensioning is performed. By assuming sufficient available power, it is possible to estimate the basic helicopter performances in both axisymmetric and progressive flight. Obtained results are presented graphically and numerically. In the end, some conclusions and recommendations for further research are given. For the time being, piston-propelled single-seat tandem helicopter can achieve better numerical results.",
publisher = "Inderscience Enterprises Ltd, Geneva",
journal = "International Journal of Sustainable Aviation",
title = "Comparative study of piston vs. electric single-seat tandem helicopter",
pages = "14-1",
number = "1",
volume = "8",
doi = "10.1504/IJSA.2022.120614"
}

Svorcan, J., Kovacević, A., Popović, L.,& Simonović, A.. (2022). Comparative study of piston vs. electric single-seat tandem helicopter. in International Journal of Sustainable Aviation
Inderscience Enterprises Ltd, Geneva., 8(1), 1-14.
https://doi.org/10.1504/IJSA.2022.120614

Svorcan J, Kovacević A, Popović L, Simonović A. Comparative study of piston vs. electric single-seat tandem helicopter. in International Journal of Sustainable Aviation. 2022;8(1):1-14.
doi:10.1504/IJSA.2022.120614 .

Svorcan, Jelena, Kovacević, Aleksandar, Popović, Lazar, Simonović, Aleksandar, "Comparative study of piston vs. electric single-seat tandem helicopter" in International Journal of Sustainable Aviation, 8, no. 1 (2022):1-14,
https://doi.org/10.1504/IJSA.2022.120614 . .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Hasan, Mohammad Sakib
AU  - Tanović, Dragoljub Lj.
AU  - Popović, Lazar
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4216
AB  - Investigated topic of the presented research is transitional and turbulent flow around smallscale
propeller blade airfoils that are characterized by small chords, low speeds and therefore, low
Reynolds numbers. Here, an airfoil of medium relative thickness designed for nominal operating
conditions of 0.3 MRe is considered. Prior studies by simpler computational models (including
panel methods and 2D CFD simulations) have demonstrated that best lift-to-drag ratio (that is the
desired working regime) ranging from 60 to 80 can be achieved at angles-of-attack 4-6°. Here,
that observation is checked by more advanced turbulence models that incorporate the resolution
of at least a portion of turbulence spectrum, in particular transition SST scale-adaptive simulation
(SAS). Such complex turbulence models require 3D models and quite refined computational
grids. Furthermore, the necessary computational effort is truly enormous due to small time-steps
and slow convergence. The conducted computational process is presented and explained. Various
obtained results, both quantitative and qualitative, are provided. In the end, it can be concluded
that the choice of turbulence modeling (and/or resolving) greatly affects the final output, even at
medium angles-of-attack where laminar, attached flow dominates. Distinctive flow phenomena
still exist, and in order to be adequately simulated, a comprehensive modeling approach should be
adopted.
PB  - Belgrade : Serbian Society of Mechanics
C3  - Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021
T1  - Simulating transitional and turbulent flow around airfoils at medium angles-of-attack
EP  - 526
SP  - 519
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4216
ER  - 

@conference{
author = "Svorcan, Jelena and Hasan, Mohammad Sakib and Tanović, Dragoljub Lj. and Popović, Lazar",
year = "2021",
abstract = "Investigated topic of the presented research is transitional and turbulent flow around smallscale
propeller blade airfoils that are characterized by small chords, low speeds and therefore, low
Reynolds numbers. Here, an airfoil of medium relative thickness designed for nominal operating
conditions of 0.3 MRe is considered. Prior studies by simpler computational models (including
panel methods and 2D CFD simulations) have demonstrated that best lift-to-drag ratio (that is the
desired working regime) ranging from 60 to 80 can be achieved at angles-of-attack 4-6°. Here,
that observation is checked by more advanced turbulence models that incorporate the resolution
of at least a portion of turbulence spectrum, in particular transition SST scale-adaptive simulation
(SAS). Such complex turbulence models require 3D models and quite refined computational
grids. Furthermore, the necessary computational effort is truly enormous due to small time-steps
and slow convergence. The conducted computational process is presented and explained. Various
obtained results, both quantitative and qualitative, are provided. In the end, it can be concluded
that the choice of turbulence modeling (and/or resolving) greatly affects the final output, even at
medium angles-of-attack where laminar, attached flow dominates. Distinctive flow phenomena
still exist, and in order to be adequately simulated, a comprehensive modeling approach should be
adopted.",
publisher = "Belgrade : Serbian Society of Mechanics",
journal = "Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021",
title = "Simulating transitional and turbulent flow around airfoils at medium angles-of-attack",
pages = "526-519",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4216"
}

Svorcan, J., Hasan, M. S., Tanović, D. Lj.,& Popović, L.. (2021). Simulating transitional and turbulent flow around airfoils at medium angles-of-attack. in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021
Belgrade : Serbian Society of Mechanics., 519-526.
https://hdl.handle.net/21.15107/rcub_machinery_4216

Svorcan J, Hasan MS, Tanović DL, Popović L. Simulating transitional and turbulent flow around airfoils at medium angles-of-attack. in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021. 2021;:519-526.
https://hdl.handle.net/21.15107/rcub_machinery_4216 .

Svorcan, Jelena, Hasan, Mohammad Sakib, Tanović, Dragoljub Lj., Popović, Lazar, "Simulating transitional and turbulent flow around airfoils at medium angles-of-attack" in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021 (2021):519-526,
https://hdl.handle.net/21.15107/rcub_machinery_4216 .

TY  - JOUR
AU  - Popović, Lazar S.
AU  - Paunović, Lazar D.
AU  - Đilas, Veljko S.
AU  - Milutinović, Aleksandar M.
AU  - Ivanov, Toni
AU  - Kostić, Ivan
PY  - 2020
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3362
AB  - Ovaj rad prezentuje metodologiju aerodinamičke optimizacije bespilotne letelice sa VTOL sposobnostima. Letelice kao što su ove obično lete pri malim brzinama, i zbog toga se očekuju mali Rejnoldsovi brojevi. Otpor trenja značajno zavisi od kvaliteta proizvodnog procesa. Prema tome, ukoliko se adekvatni koraci ne preduzmu, javiće se visoki koeficijenti trenja koji mogu drastično da promene performanse letelice. Promene geometrijskih parametara ne utiču samo na indukovani otpor krila, zbog osetljivosti na promene Rejnoldsovog broja utiču i na raspodelu profilnog otpora. Napisan je kod za proračun aerodinamičkih karakteristika krila zarad određivanja optimalnih geometrijskih parametara. Svi neophodni koeficijenti su izračunati korišćenjem Galuertovog rešenja Prantlove jednačine primenjenim na višesegmentna krila. Implementacijom aerodinamičkih koeficijenata brojnih eksperimentalno ispitanih aeroprofila optimizovanim za male Rejnoldsove brojeve, raspodela profilnog otpora, i indukovani otpor krila za veliki broj napadnih uglova su izračunati. Dobijeni rezultati su predstavljeni dijagramima, a metodologija za izbor najefikasnijeg krila je opisana. Dizajn T-oblika repnih površina je izvršen analitičkom metodom, dok su metoda vrtložne mreže, DATCOM, i CFD korišćeni za potrebe verifikacije rezultata.
AB  - This paper presents a methodology for aerodynamic optimization of UAV with VTOL capabilities. Aircrafts such as these usually fly at low speeds and due to that low Reynolds numbers are to be expected. The friction drag is highly dependent on the quality of the production process so unless special measures are undertaken, high friction drag coefficients could drastically influence overall performance of the aircraft. Changes of the geometrical parameters influence not only the induced drag of the wing, but also the distribution of the base drag due to sensitivity to changes of the Reynolds numbers. In order to determine the optimal geometrical parameters of the wing, a code for wing performance analysis was written. All necessary factors were calculated by utilizing the Glauert's solution of the Prandtl's equation for multi-segmented wings. By including experimental data of numerous airfoils optimized for low Reynolds numbers, the base drag distribution, along with the induced drag of the wings were calculated for a wide range of angles-of-attack. The obtained results are presented through diagrams and the methodology for the selection of the highest efficiency wing is described. The design of the T - shaped stabilizer was achieved by utilizing analytical methods while the Vortex Lattice Method, DATCOM and CFD were used for verification purposes.
PB  - Vojnotehnički institut, Beograd
T2  - Scientific Technical Review
T1  - Aerodinamički dizajn bespilotne letelice u više faza
T1  - Design of the UAV aerodynamics in multiple stages
EP  - 16
IS  - 2
SP  - 9
VL  - 70
DO  - 10.5937/str2002009P
ER  - 

@article{
author = "Popović, Lazar S. and Paunović, Lazar D. and Đilas, Veljko S. and Milutinović, Aleksandar M. and Ivanov, Toni and Kostić, Ivan",
year = "2020",
abstract = "Ovaj rad prezentuje metodologiju aerodinamičke optimizacije bespilotne letelice sa VTOL sposobnostima. Letelice kao što su ove obično lete pri malim brzinama, i zbog toga se očekuju mali Rejnoldsovi brojevi. Otpor trenja značajno zavisi od kvaliteta proizvodnog procesa. Prema tome, ukoliko se adekvatni koraci ne preduzmu, javiće se visoki koeficijenti trenja koji mogu drastično da promene performanse letelice. Promene geometrijskih parametara ne utiču samo na indukovani otpor krila, zbog osetljivosti na promene Rejnoldsovog broja utiču i na raspodelu profilnog otpora. Napisan je kod za proračun aerodinamičkih karakteristika krila zarad određivanja optimalnih geometrijskih parametara. Svi neophodni koeficijenti su izračunati korišćenjem Galuertovog rešenja Prantlove jednačine primenjenim na višesegmentna krila. Implementacijom aerodinamičkih koeficijenata brojnih eksperimentalno ispitanih aeroprofila optimizovanim za male Rejnoldsove brojeve, raspodela profilnog otpora, i indukovani otpor krila za veliki broj napadnih uglova su izračunati. Dobijeni rezultati su predstavljeni dijagramima, a metodologija za izbor najefikasnijeg krila je opisana. Dizajn T-oblika repnih površina je izvršen analitičkom metodom, dok su metoda vrtložne mreže, DATCOM, i CFD korišćeni za potrebe verifikacije rezultata., This paper presents a methodology for aerodynamic optimization of UAV with VTOL capabilities. Aircrafts such as these usually fly at low speeds and due to that low Reynolds numbers are to be expected. The friction drag is highly dependent on the quality of the production process so unless special measures are undertaken, high friction drag coefficients could drastically influence overall performance of the aircraft. Changes of the geometrical parameters influence not only the induced drag of the wing, but also the distribution of the base drag due to sensitivity to changes of the Reynolds numbers. In order to determine the optimal geometrical parameters of the wing, a code for wing performance analysis was written. All necessary factors were calculated by utilizing the Glauert's solution of the Prandtl's equation for multi-segmented wings. By including experimental data of numerous airfoils optimized for low Reynolds numbers, the base drag distribution, along with the induced drag of the wings were calculated for a wide range of angles-of-attack. The obtained results are presented through diagrams and the methodology for the selection of the highest efficiency wing is described. The design of the T - shaped stabilizer was achieved by utilizing analytical methods while the Vortex Lattice Method, DATCOM and CFD were used for verification purposes.",
publisher = "Vojnotehnički institut, Beograd",
journal = "Scientific Technical Review",
title = "Aerodinamički dizajn bespilotne letelice u više faza, Design of the UAV aerodynamics in multiple stages",
pages = "16-9",
number = "2",
volume = "70",
doi = "10.5937/str2002009P"
}

Popović, L. S., Paunović, L. D., Đilas, V. S., Milutinović, A. M., Ivanov, T.,& Kostić, I.. (2020). Aerodinamički dizajn bespilotne letelice u više faza. in Scientific Technical Review
Vojnotehnički institut, Beograd., 70(2), 9-16.
https://doi.org/10.5937/str2002009P

Popović LS, Paunović LD, Đilas VS, Milutinović AM, Ivanov T, Kostić I. Aerodinamički dizajn bespilotne letelice u više faza. in Scientific Technical Review. 2020;70(2):9-16.
doi:10.5937/str2002009P .

Popović, Lazar S., Paunović, Lazar D., Đilas, Veljko S., Milutinović, Aleksandar M., Ivanov, Toni, Kostić, Ivan, "Aerodinamički dizajn bespilotne letelice u više faza" in Scientific Technical Review, 70, no. 2 (2020):9-16,
https://doi.org/10.5937/str2002009P . .