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박재현(Jae Hyeon Park),손동경(Dong Kyung Sohn),김창현(Chang Hyun Kim),백제현(Je Hyun Baek) 대한기계학회 2016 大韓機械學會論文集B Vol.40 No.2
터보기계 내부 유동장은 역압력구배, 고속 유동으로 인해 매우 복잡하며, 이를 해석하기 위해 보다 정교한 난류 모델이 요구된다. 유동 해석을 위해 대수모델, 2-방정식 와점도 모델 등이 널리 사용되고 있으나, 매우 복잡한 유동을 모사하는데 어려움이 있다. 본 연구에서는 복잡한 유동에서의 예측성능이 우수하다고 알려진 Durbin의 V2-F 난류 모델을 자체 개발 코드인 T-Flow에 적용하였으며, 채널 및 압축기 캐스캐이드 유동 해석 결과를 이용하여 난류 모델을 검증하였다. 또한 저속 압축기 동익 해석을 통해 터보기계 내부 유동에서의 적용 가능성을 판단하였다. 그 결과, V2-F난류 모델은 1-방정식, 2방정식 난류 모델보다 우수한 블레이드 표면 압력 분포 예측성능을 보였다. Since a turbomachine has complex flow characteristics, which are caused by adverse pressure gradient and high speed motion, an elaborate turbulence model is needed to accurately predict the flow. Some turbulence models such as an algebraic or a two-equation eddy viscosity model have been used for in-house RANS-code, but it is difficult to obtain good result for several complex flows. In this study, Durbin‘s V2-F turbulence model, which has been known for better prediction for severe flow separation, is applied to T-Flow. It was validated for simple cases such as channel and compressor cascade, and its applicability to turbomachinery was shown by analyzing internal flow of a single rotor. As a result, the V2-F turbulence model shows better blade surface pressure distribution than the one-and-two equation turbulence model.
배준호(June-ho Bae),손동경(Dong-kyung Sohn) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11
This paper aims to verify the applicability of open source code, OpenFOAM, to internal flows for the use of nuclear power plant flow simulation. For the verification, several representative flow cases are selected (Plain Couette flow with Pressure Gradient, Cavitation over a sharp-edged circular orifice, Converging-Diverging Nozzle). The simulation results are compared with experimental or theoretical result. Result from Plain Couette flow is similar with analytical solution. And for the Cavitation over a sharp-edged circular orifice, the coefficient of discharge, C<SUB>d</SUB>, is evaluated by experimental result. The Converging-Diverging Nozzle is compressible flow simulation from subsonic to supersonic flow fields. It shows that the flow fields are similar with analytical solution and the location of shock are well predicted. Based on this research, future study using OpenFoam is proposed.