Numerical study on various vortices in pump sump based on LBM-LES

29th IAHR Symposium on Hydraulic Machinery and Systems

Lei, Jun^1 ; Tang, Xuelin^1^2 ; Li, Xiaoqin^1^2 ; Guo, Miao^1

College of Water Resources and Civil Engineering, China Agricultural University, Beijing

100083, China^1

Beijing Engineering Research Centre of Safety, Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing

100083, China^2

关键词: Free-surface vortices;    Lattice Boltzmann method;    LBM-LES;    Performance optimizations;    Peripheral velocity;    Pump sump;    Structural improvements;    Velocity variations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/7/072022/pdf
DOI  :  10.1088/1755-1315/240/7/072022

来源: IOP

【 摘 要 】

The complex flow pattern in the intake sump of pump station affects the safe operation of the pump unit, and therefore it is particularly important to analyse the causes and the evolution of various vortex. In this paper, the combined model based on LBM (Lattice Boltzmann Method) and LES (Large Eddy Simulation) is used to investigate the flow pattern, where the rigid-lid assumption is employed to deal with the free surface in the intake sump. The numerical results show that, the free surface vortex forms behind the pump bell and rotates in anti-clockwise direction, there exists one vortex separately near the bottom parts of both side walls and there is a low velocity recirculation zone near the bottom of the center of the back wall. The velocity variation of the vortex core of subsidence vortex at different depths below the free surface demonstrated that the peripheral velocity has the minimum value at the center of the vortex core. The predicted flow pattern is in accordance with the actual rule, and the location, shape and size of the free surface vortex in the water intake are captured well, all the analyses and comparisons showed that the LBM-LES model and the rigid-lid assumption method is more accurate to simulate the free surface vortex, and can provide guidance for structural improvement and performance optimization of the pump sump.