喷水推进轴流泵汽蚀性能RANS模拟与不确定度分析

RANS Simulation and Uncertainty Analysis of Cavitation for Axial-Flow Waterjet Pump

对模型尺度的喷水推进轴流泵汽蚀性能进行了准定常RANS模拟,并根据第28届国际拖曳水池会议推荐的规程进行了数值不确定度分析。采用Realizable k-ε2层模型,并采用细化的边界层网格直接解析黏性底层流动。控制方程采用2阶格式离散和SIMPLE算法求解;计算域采用分块六面体结构化单元离散,并采用3套具有相同细化比的网格进行流动计算与数值不确定度分析,结果表明:模拟结果的数值不确定度不超过2%,汽蚀余量预报具有较高的精度。

Quasi-steady RANS simulations of an axial-flow pump for waterjet propulsion at model scale are carried out,and the numerical uncertainties in the simulations are analyzed according to the procedure recommended by the 28th International Towing Tank Conference.The two-layer realizable k-εmodel is employed to simulate turbulent flow,and the flow in viscous sub-layer is resolved by refining boundary-layer grids.The governing equations are discretized with 2nd-order schemes,and solved by using the SIMPLE scheme.The computational domain is discretized with block-structured hexahedral cells.The uncertainty analysis is performed according to the simulation results yielded from 3 sets of grids having uniform grid refinement ratios.It is verified that the simulation uncertainty does not exceed 2%,and the cavitation performance is accurately predicted.