径向和轴向间隙对喷水推进轴流泵特性影响数值分析  

Effect of Clearance on Performance of Waterjet Axial Flow Pump

作　　者：胡明华[1] 

机构地区：[1]江苏海事职业技术学院,南京211170

出　　处：《中国航海》2017年第3期20-24,共5页Navigation of China

摘　　要：采用三维雷诺平均N-S方程和S-A湍流模型对不同叶轮间隙的喷水推进轴流泵流场及水力性能进行数值计算。计算中选取的相对径向间隙δ(径向间隙尺寸与叶轮直径之比)分别为0.2%,0.4%,0.6%和0.8%,选取的轴向间隙分别为10 mm,15 mm,20 mm和25 mm。计算结果表明:随着δ的增大,泵模型水力性能降低;当δ增大到0.6%时,小流量工况下泵模型的效率和扬程下降加快,设计工况下的叶片进口形成泄漏涡,泄漏损失增大;当轴向间隙增大到20 mm时,静叶吸力面出现分离螺旋点,易引发汽蚀,泵模型选用的轴向间隙为15 mm。The three dimensional Reynolds averaged N-S equation and the S-A turbulent model are used to simulate the flow field and hydraulic performance of the waterjet axial flow pump with the different impeller clearance. For simulation,the relative tip clearance δ（ the ratio of the tip clearance and the impeller diameter） is set to 0. 2%,0. 4%,0. 6% and 0. 8%while the axial clearance is chosen from the set of 10 mm,15 mm,20 mm,25 mm. The numerical research results show that the hydraulic performance of the pump goes down as the relative tip clearance increases. Under the small flow rate conditions,when relative tip clearance increases to 0. 6%,the efficiency and the head of pump decrease sharply,meanwhile the tip leakage vortex is formed in the inlet zone of the impeller under the designed working condition,causing leakage loss increase. When the axial clearance increases to 20 mm,the separation point appears on the suction surface of the stator,which may cause cavitation,therefore,the axial clearance of 15 mm is set in the model of the pump.

关 键 词：船舶工程 喷水推进泵 径向间隙 轴向间隙 数值计算 

分 类 号：U664.34[交通运输工程—船舶及航道工程]