Modeliranje i numeričke simulacije vihornih strujanja
Modeling and numerical simulations of swirling flows
2013
Autori
Ćoćić, AleksandarOstala autorstva
Čantrak, SvetislavCrnojević, Cvetko
Ivetić, Marko
Stevanović, Nevena
Lečić, Milan
Doktorska teza (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt
Vihorna strujanja su veoma prisutna u tehničkoj praksi...
Swirling flows are very common in technical practice. Flows in turbomachinery and rotating systems, flows in pipelines after local resistances, flows of air in cyclones and combustion chambers are just few examples of swirling flows in technical practice. Turbulence structure in swirling flows are highly inhomogeneous and anisotropic. In most cases turbulent models based on Boussinesq, linear eddy viscosity assumption, give poor results. That is specially pronounced in case of Rankine type profile for circumferential velocity. Reynolds stress models give better results in prediction of swirling flows, but their usage in complex geometries are very demanding from the viewpoint of solution convergence and time of calculation. In this thesis main accent of research is on numerical simulations of swirling flows by use of various turbulent models, and on theoretical analysis of the models and numerical methods which are used for computations. An open-source software OpenFOAM was used for al...l computations. Due to openness of the OpenFOAM code, it’s possible to analyze the way of implementation of various mathematical models. Based on the code analysis, Speziale-Sarkar-Gatski (SSG) Reynolds stress model was implemented in OpenFOAM code. Also, some additional postprocessing tools and applications were created and implemented in the code. Two problems are considered: axisymmetric swirl flow in long circular pipe with Rankine profile of circumferential velocity, and three-dimensional swirl flow in the pipe behind axial fan. In first problem, swirl generator wasn’t considered, and experimental results in one cross-section were used as boundary condition at the inlet. As a validation tool for numerical computations, experimental results in other cross-sections were used. Several turbulent models were tested on this problem. From class of two equation models k-", RNG k-", Launder-Sharma k-" and k-! SST models were used, while from Reynolds stress models class Launder-Reece-Rodi (LRR), Launder-Gibson (LG) and SSG model were used. It was shown that all two-equation models give poor results, both for profiles of mean velocities, and for turbulent kinetic energy. Reynolds stress models give better results for mean velocity profiles...
Ključne reči:
vihorna strujanja / turbulentni model / OpenFOAM / obimska brzina / numerička mehanika fluida / turbulent model / swirling flows / OpenFOAM / computational fluid dynamics / circumferential velocityIzvor:
2013Izdavač:
- Univerzitet u Beogradu, Mašinski fakultet
Finansiranje / projekti:
- Primena savremenih mernih i proračunskih tehnika za izučavanje strujnih parametara ventilacionih sistema na modelu energetski izuzetno efikasnog (pasivnog) objekta (RS-MESTD-Technological Development (TD or TR)-35046)
URI
http://eteze.bg.ac.rs/application/showtheses?thesesId=1645https://nardus.mpn.gov.rs/handle/123456789/2325
https://fedorabg.bg.ac.rs/fedora/get/o:9161/bdef:Content/download
http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=514394019
https://machinery.mas.bg.ac.rs/handle/123456789/21
Kolekcije
Institucija/grupa
Mašinski fakultetTY - THES AU - Ćoćić, Aleksandar PY - 2013 UR - http://eteze.bg.ac.rs/application/showtheses?thesesId=1645 UR - https://nardus.mpn.gov.rs/handle/123456789/2325 UR - https://fedorabg.bg.ac.rs/fedora/get/o:9161/bdef:Content/download UR - http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=514394019 UR - https://machinery.mas.bg.ac.rs/handle/123456789/21 AB - Vihorna strujanja su veoma prisutna u tehničkoj praksi... AB - Swirling flows are very common in technical practice. Flows in turbomachinery and rotating systems, flows in pipelines after local resistances, flows of air in cyclones and combustion chambers are just few examples of swirling flows in technical practice. Turbulence structure in swirling flows are highly inhomogeneous and anisotropic. In most cases turbulent models based on Boussinesq, linear eddy viscosity assumption, give poor results. That is specially pronounced in case of Rankine type profile for circumferential velocity. Reynolds stress models give better results in prediction of swirling flows, but their usage in complex geometries are very demanding from the viewpoint of solution convergence and time of calculation. In this thesis main accent of research is on numerical simulations of swirling flows by use of various turbulent models, and on theoretical analysis of the models and numerical methods which are used for computations. An open-source software OpenFOAM was used for all computations. Due to openness of the OpenFOAM code, it’s possible to analyze the way of implementation of various mathematical models. Based on the code analysis, Speziale-Sarkar-Gatski (SSG) Reynolds stress model was implemented in OpenFOAM code. Also, some additional postprocessing tools and applications were created and implemented in the code. Two problems are considered: axisymmetric swirl flow in long circular pipe with Rankine profile of circumferential velocity, and three-dimensional swirl flow in the pipe behind axial fan. In first problem, swirl generator wasn’t considered, and experimental results in one cross-section were used as boundary condition at the inlet. As a validation tool for numerical computations, experimental results in other cross-sections were used. Several turbulent models were tested on this problem. From class of two equation models k-", RNG k-", Launder-Sharma k-" and k-! SST models were used, while from Reynolds stress models class Launder-Reece-Rodi (LRR), Launder-Gibson (LG) and SSG model were used. It was shown that all two-equation models give poor results, both for profiles of mean velocities, and for turbulent kinetic energy. Reynolds stress models give better results for mean velocity profiles... PB - Univerzitet u Beogradu, Mašinski fakultet T1 - Modeliranje i numeričke simulacije vihornih strujanja T1 - Modeling and numerical simulations of swirling flows UR - https://hdl.handle.net/21.15107/rcub_nardus_2325 ER -
@phdthesis{ author = "Ćoćić, Aleksandar", year = "2013", abstract = "Vihorna strujanja su veoma prisutna u tehničkoj praksi..., Swirling flows are very common in technical practice. Flows in turbomachinery and rotating systems, flows in pipelines after local resistances, flows of air in cyclones and combustion chambers are just few examples of swirling flows in technical practice. Turbulence structure in swirling flows are highly inhomogeneous and anisotropic. In most cases turbulent models based on Boussinesq, linear eddy viscosity assumption, give poor results. That is specially pronounced in case of Rankine type profile for circumferential velocity. Reynolds stress models give better results in prediction of swirling flows, but their usage in complex geometries are very demanding from the viewpoint of solution convergence and time of calculation. In this thesis main accent of research is on numerical simulations of swirling flows by use of various turbulent models, and on theoretical analysis of the models and numerical methods which are used for computations. An open-source software OpenFOAM was used for all computations. Due to openness of the OpenFOAM code, it’s possible to analyze the way of implementation of various mathematical models. Based on the code analysis, Speziale-Sarkar-Gatski (SSG) Reynolds stress model was implemented in OpenFOAM code. Also, some additional postprocessing tools and applications were created and implemented in the code. Two problems are considered: axisymmetric swirl flow in long circular pipe with Rankine profile of circumferential velocity, and three-dimensional swirl flow in the pipe behind axial fan. In first problem, swirl generator wasn’t considered, and experimental results in one cross-section were used as boundary condition at the inlet. As a validation tool for numerical computations, experimental results in other cross-sections were used. Several turbulent models were tested on this problem. From class of two equation models k-", RNG k-", Launder-Sharma k-" and k-! SST models were used, while from Reynolds stress models class Launder-Reece-Rodi (LRR), Launder-Gibson (LG) and SSG model were used. It was shown that all two-equation models give poor results, both for profiles of mean velocities, and for turbulent kinetic energy. Reynolds stress models give better results for mean velocity profiles...", publisher = "Univerzitet u Beogradu, Mašinski fakultet", title = "Modeliranje i numeričke simulacije vihornih strujanja, Modeling and numerical simulations of swirling flows", url = "https://hdl.handle.net/21.15107/rcub_nardus_2325" }
Ćoćić, A.. (2013). Modeliranje i numeričke simulacije vihornih strujanja. Univerzitet u Beogradu, Mašinski fakultet.. https://hdl.handle.net/21.15107/rcub_nardus_2325
Ćoćić A. Modeliranje i numeričke simulacije vihornih strujanja. 2013;. https://hdl.handle.net/21.15107/rcub_nardus_2325 .
Ćoćić, Aleksandar, "Modeliranje i numeričke simulacije vihornih strujanja" (2013), https://hdl.handle.net/21.15107/rcub_nardus_2325 .