Abstract In order to clarify the mixing process between the working fluid and the sucked fluid in a jet pump, several twoequation turbulence models (Standard k-ε, RNG k-ε, Realizable k-ε and SST k-ω model) and Large Eddy Simulation model were used to calculate 3D singlephase flow field in the pump, and the numerical results were compared with the experimental data. The results showed that the pressure ratio and efficiency obtained by LES model agreed well with the experimental data. All the above twoequation turbulence models overestimated the energy dissipation during the mixing process and the vortex structure in the mixing layer was not well predicted by them. Just the LES model, however, showed the coherent vortex structure in the mixing layer, which precisely reflects the transport of momentum and energy, and the mixing process between the working fluid and sucked fluid. Further the predicted characteristic curves by LES achieved better agreement with the experimental observations than those by the rest turbulence models. Then LES was chosen to simulate the internal flow of the jet pump at different flow ratios. The results showed that the mixing zone between the working fluid and the sucked fluid moved away from the throat to downstream with increasing flow ratio; consequently the core flow with high velocity is stretched along the axial direction and the axial velocity of the mixed fluid is also increased.
ZHOU Ling-Jiu,YUAN Ling-Li. Comparison of internal flows in jet pump predicted by various turbulence models[J]. Journal of Drainage and Irrigation Machinery Engin, 2013, 31(1): 25-30.
Yamazaki Yukitaka, Yamazaki Atsushi, Narabayashi Tadashi, et al. Studies on mixing process and performance improvement of jet pumps:Effects of nozzle and throat shapes [J]. Journal of Fluid Science and Technology, 2007,2 (1): 238-247.
Huang Jianfeng, Zhang Lixiang, Wang Wenquan, et al. Large eddy simulation of transient turbulent flow in Francis turbine[J]. Journal of Drainage and Irrigation Machinery Engineering, 2010,28(6): 502-505.(in Chinese)
Karabelas S J. Large eddy simulation of highReynolds number flow past a rotating cylinder[J]. International Journal of Heat and Fluid Flow, 2010, 31(4): 518-527.
Wang Chunlin, Si Yanlei, Zhao Baitong, et al. Large eddy simulation on interior flow field of rotational rlow selfpriming pump[J]. Transactions of the Chinese Society for Agricultural Machinery, 2009, 40(9): 68-72,97.(in Chinese)
Wen Jiyun, Yu Bo, Lu Hongqi, et al. Large eddy simulation for jet pump flow[J]. Engineering Journal of Wuhan University, 2007,40(2): 110-114.(in Chinese)
Long Xinping, Han Ning, Chen Qian. Influence of nozzle exit tip thickness on the performance and flow field of jet pump[J]. Journal of Mechanical Science and Technology, 2008,22:1959-1965.
于凤荣,闰国军,张建蓉. 射流泵流场三维数值模拟［J］. 水泵技术,2006 (6):21-23.
Yu Fengrong, Run Guojun, Zhang Jianrong. 3D numerical simulation of jet pump[J]. Pump Technology, 2006(6):21-23.(in Chinese)
蔡标华. 射流泵初生空化及其试验研究［D］. 武汉:武汉大学动力与机械学院,2005.
Lu Changgen, Cao Weidong, Qian Jianhua. A study on numerical method of Navier-Stokes equation and nonlinear evolution of the coherent structures in a laminar boundary layer[J]. Journal of Hydrodynamics, 2006, 18(3):372377.