不同工况下无轴泵喷推进器间隙流动损耗特性数值分析  

Numerical analysis on clearance flow loss of shaftless pump-jet thruster under different conditions

作　　者：韩承灶 阮华[2] 洪方文[2] 季斌 Cheng-zao Han;Hua Ruan;Fang-wen Hong;Bin Ji(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;Key Laboratory on Ship Vibration&Noise,China Ship Science Research Center,Wuxi 214082,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [2]中国船舶科学研究中心船舶振动噪声重点实验室,无锡214082

出　　处：《水动力学研究与进展（A辑）》2022年第1期1-9,共9页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金面上项目(52176041)。

摘　　要：为研究无轴泵喷推进器间隙流动特性以及流动损耗机理,采用雷诺平均(RANS)方程对不同工况下无轴泵喷推进器周围流场进行数值模拟。该文首先进行了推进器水动力性能计算,通过与试验结果的比较,评估了湍流模型和网格数量对结果的影响。在此基础上,进一步采用柱坐标系下涡量输运方程和熵增理论,分析了不同工况下推进器间隙流动特征和能量损耗机理。结果表明,计算结果与试验吻合程度较高;进一步由涡量输运方程分析可得方程右侧其影响涡量输运的各项多集中于间隙及间隙进出口区域,其中黏性耗散项对间隙区涡量变化起到主要作用,加剧流动不稳定性;由熵增结果可知,间隙区域中由黏性耗散引起的功率损失占据主导地位,由湍流耗散产生的损失可以忽略不计;同时,间隙流出口区由于流体流动方向与主流方向垂直,二者相互碰撞的同时受到叶轮抽吸作用向下游运动,导致该区域流动较为复杂,流动损耗较大;且随着进速系数提高,由轮缘所引发的流动损耗对推进器水动力性能有一定影响。In order to study the clearance flow characteristic and loss mechanism of shaftless pump-jet,the Reynolds average simulation(RANS)approach is used to simulate the flow field around the propulsion pump.In this paper,the hydrodynamic performance of the pump is calculated firstly,and the influence of the turbulence model and the number of grids on the results is evaluated by comparing with the experiments.On this basis,the vorticity transport equation in the cylindrical coordinate system and the entropy production are further used to analyze the clearance flow characteristics and energy loss mechanism of the propeller under different working conditions,the calculated results are in good agreement with the test.Further analysis of the vorticity transport equation shows that on the right side of the equa tion,the items affecting vorticity transport are mostly concentrated in the gap and the gap entrance and exit areas,in which the viscous dissipation term plays a major role in the clearance area vorticity change,and aggravates the flow instability.It can be seen from the result of entropy production that the power loss caused by viscous dissipation in the gap area is dominant,and the loss ca used by turbulent dissipation can be ignored.Because the flow direction of the fluid in the gap outlet area is perpendicular to the main flow direction,the two collide with each other while being sucked by the impeller and move downstream,resulting in more complex fl ow and loss in this area.As the advancement coefficient increases,the flow loss caused by the rim has a certain impact on the hydrody namic performance of the pump.

关 键 词：无轴泵喷 间隙流动 涡量输运 数值分析 熵增理论 

分 类 号：TJ6[兵器科学与技术—武器系统与运用工程]