Numerical simulation of vortical wake flow of a micro-vortex generator by using non-equilibrium Eddy Viscosity Model비평형 와점성 모형을 이용한Micro-Vortex Generator후류의 수치 모사

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dc.contributor.advisorPark, Seung-O-
dc.contributor.advisor박승오-
dc.contributor.authorBhattarai, Nikesh-
dc.contributor.authorBhattarai, Nikesh-
dc.date.accessioned2015-04-23T02:06:04Z-
dc.date.available2015-04-23T02:06:04Z-
dc.date.issued2013-
dc.identifier.urihttp://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=567105&flag=dissertation-
dc.identifier.urihttp://hdl.handle.net/10203/196125-
dc.description학위논문(석사) - 한국과학기술원 : 항공우주공학전공, 2013.8, [ vi, 56 p. ]-
dc.description.abstractReynolds Averaged Navier-Stokes (RANS) simulations using Non-equilibrium Eddy Viscosity Model as proposed by Akira Yoshizawa has been implemented into k-omega SST model of Menter to simulate for flow around a single rectangular Micro-Vortex Generator placed on a flat plate, skewed at three different angles (10 o, 16 o & 23o). Conventional two-equation models perform rather poorly for flows that are not in near-equilibrium state. These turbulence models are based on single-time-scale schemes. Flow past a vortex generator produces tip vortices which are highly non-equilibrium in nature. Hence, the Non-equilibrium eddy viscosity model as proposed by Yoshizawa et al. has been employed in this study. Yoshizawa’s Non-equilibrium eddy viscosity model takes into account a non-stationary or non-equilibrium effect in time scale of turbulence. This is synthesized by combining several characteristic time scales; mean-strain, mean-vorticity and also frame-rotation effect on dissipation rate equation. This modification results in reduction of eddy viscosity in swirling flows. Experimental and CFD database of Yao and Lin has been taken as a reference case for the present study. GAMBIT is used to generate structured mesh for the entire computational domain and simulations are performed in OpenFOAM in which simpleFOAM, a steady state solver for incompressible, turbulent flow; is employed. Computational results indicate that the characteristics of the tip vortex for the MVG are much better predicted by employing this Non-equilibrium eddy viscosity model compared to the original k-omega SST model of Menter. Non-equilibrium eddy viscosity model reduces the estimation of turbulent eddy viscosity in the vortex core region compared to the k-omega SST model which leads to better prediction of vortex features of the MVG cases. Vortex path, both in vertical and lateral directions obtained from Non-equilibrium eddy viscosity model follow the same trend as that of k-omega SST model. The...eng
dc.languageeng-
dc.publisher한국과학기술원-
dc.subject미소 와류 발생기-
dc.subject비평형 와점성 모델-
dc.subjectGAMBIT-
dc.subjectOpenFOAM-
dc.subjectk-omega SST 모델-
dc.subjectNon-equilibrium Eddy Viscosity Model-
dc.subjectMicro-Vortex Generator-
dc.subjectk-omega SST model-
dc.subjectGAMBIT-
dc.subjectOpenFOAM-
dc.titleNumerical simulation of vortical wake flow of a micro-vortex generator by using non-equilibrium Eddy Viscosity Model-
dc.title.alternative비평형 와점성 모형을 이용한Micro-Vortex Generator후류의 수치 모사-
dc.typeThesis(Master)-
dc.identifier.CNRN567105/325007 -
dc.description.department한국과학기술원 : 항공우주공학전공, -
dc.identifier.uid020114557-
dc.contributor.localauthorPark, Seung-O-
dc.contributor.localauthor박승오-
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AE-Theses_Master(석사논문)
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