Numerical study of air-entraining and submerged vortices in a pump sump

29th IAHR Symposium on Hydraulic Machinery and Systems

Yanase, Shinichiro^1 ; Yamasaki, Ryo^2 ; Kouchi, Toshinori^1 ; Hosoda, Shunsuke^1 ; Nagata, Yasunori^1 ; Shunji, Higuchi^2 ; Kawabe, Toshihiko^2 ; Takami, Toshihiro^3

Department of Mechanical and Systems Engineering, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama-shi, Okayama

700-8530, Japan^1

Technical Division, Tsurumi Manufacturing Co., 2700 Yomi-cho, Yonago-shi, Tottori

683-0851, Japan^2

Department of Mechanical and Systems Engineering, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama-shi, Okayama

700-0005, Japan^3

关键词: Benchmark experiments;    Detection methods;    Gas liquids;    Grid density;    Grid systems;    Smagorinsky model;    Submerged vortices;    Velocity gradients;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/3/032001/pdf
DOI  :  10.1088/1755-1315/240/3/032001

来源: IOP

【 摘 要 】

Numerical detection of harmful vortices in pump sumps, such as an air-entraining vortex (AEV) and a submerged vortex (SMV), is crucially important to develop the drain pump machinery. We performed numerical simulations of the benchmark experiments of the pump sump conducted by Matsui et al. (2006 and 2016) using the OpenFOAM and compared the simulation results with the experimental data considering the effects of turbulence model, grid density and detection method of the vortices. We studied the threshold of the gas-liquid volume fraction of the VOF method and the second invariant of velocity gradient tensor to identify AEV and SMV. The methods proposed in the present paper were found to be very effective for the detection of the vortices, and the simulation results by RANS with the SST k-ω model successfully reproduced the experimental data. LES with the Smagorinsky model, however, was sensitive to the grid system and difficult to reproduce the experimental data even for the finest grid system having 3.7 million cells in the present study.