不同流量工况下混流式喷水推进泵涡流所致能量损失  

Vortex-induced energy loss of a mixed-flow waterjet pump under different operating conditions

作　　者：阙阙 徐宇航 徐辉 冯建刚 杨子轩 Kan Kan;Yuhang Xu;Hui Xu;Jiangang Feng;Zixuan Yang(College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;College of Agricultural Science and Engineering,Hohai University Nanjing 210098,China;Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China [2]College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China [3]College of Agricultural Science and Engineering,Hohai University Nanjing 210098,China [4]Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Acta Mechanica Sinica》2023年第9期39-51,共13页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.52009033,11972038);the Natural Science Foundation of Jiangsu Province(Grant No.BK20200509);the Postdoctoral Research Foundation of China(Grant Nos.2022M711021,2021M690876).

摘　　要：混流式喷水推进泵(M-FWPs)是高速船舶动力推进的核心部件.当其在非最优工况下运行时,流道中的不稳定流动会导致泵效率的下降。本文通过数值模拟,基于熵产理论研究了在不同工况下的能量损失机理。对仿真数据的分析表明,熵产率主要由流耗散产生.通过比较速度梯度、涡度、动能以及动能耗散的相关性,发现在非最优工况下,由于叶轮进口入流角与叶片前缘进口角的不匹配,会导致流动分离和大尺度漩涡等非稳定流动结构的发生,这些非定常流动现象所导致的涡量和端动能增强最终引起了熵增.进一步检验拟涡能的输运发现涡生成项在非定常流动的产生过程中扮演了主要角色.Mixed-flow waterjet pumps(M-FWPs)are core units of high-speed ship power propulsion.When operated under non-optimal operating conditions,the unstable flow generated in the flow passage leads to a reduction in pump efficiency.This article investigates the energy loss mechanism of M-FWPs under different operating conditions through entropy production theory based on numerical simulations.The analyses of the simulation data show that the turbulence dissipation(EPTD)makes the dominant contribution to the entropy production rate.By comparing the correlations of velocity gradient,vorticity,and turbulent kinetic energy(TKE)with the EPTD,it is discovered that under non-optimal operating conditions,the inflow angle at the impeller inlet does not match the blade inlet angle at the leading edge of the blade,resulting in unsteady flow structures such as flow separation and large-scale vortices.The increase in vorticity and TKE caused by these unsteady structures ultimately causes the generation of turbulent entropy.Further examination of the enstrophy transport equation indicates that the relative vortex generation term plays a dominant role in the development of the unsteady flow in the flow passage.

关 键 词：不稳定流动 最优工况 叶轮进口 非定常流动 非稳定流动 进口角 损失机理 混流式 

分 类 号：O3[理学—力学]