复合叶片对小流量工况下燃油离心泵非定常特性的影响

Simulation on Transient Flow Characteristics for an Aero-Fuel Centrifugal Pump with Combination Blades under Condition of Low Flowrate

关键词:  燃油离心泵  复合叶片  非定常特性  小流量  数值计算

Key words:  Aero-fuel centrifugal pump  Combination blade  Unsteady characteristics  Low flowrate  Numerical simulation

摘要:

为了研究长中短复合叶片对小流量工况下燃油离心泵非定常特性的影响规律，基于CFD技术对某型燃油离心泵进行了非定常数值模拟。首先，分别建立原型方案和带有长中短复合叶片的优化方案的离心泵三维模型和网格模型。其次，基于RNG k-ε湍流模型，对两个方案中泵内流动非定常特性进行数值计算。仿真结果表明：长中短复合叶片减弱了叶轮流道内的大尺度漩涡，降低了叶轮的出口滑移，使得压力分布更加均匀。同时，叶轮与隔舌的动静干涉造成了蜗壳内一定程度的压力脉动产生，且长中短复合叶片的压力脉动幅值相对较低。另一方面，小流量工况下，优化方案中离心泵的增压值为12.9MPa，效率为26.9%，比原型方案中离心泵的增压值和效率分别提高了3.5%和2.6%。

Abstract:

In order to study the effects of long， medium and short combination blades on the unsteady characteristics of aero-fuel centrifugal pumps under the small flow conditions， transient simulation is performed for a certain type of aero-fuel centrifugal pump based on CFD technology. Firstly， 3D models and mesh models of centrifugal pumps with prototype scheme and optimization scheme with compound impeller are established. Secondly， based on the RNG k-ε turbulence model， numerical transient simulations for unsteady characteristics of the flow in the pump in the two schemes are conducted. The simulation results show that the long， medium and short combination blades can reduce the large-scale vortices in the impeller flow channels， where the impeller exit slip is reduced and the pressure distribution is demonstrated more uniform. Moreover， certain pressure pulsation in the volute is caused due to the rotor-stator interaction between the impeller and the tongue nearby the volute tongue， and it shows relatively low in the combination blades. In addition， compared with the protype pump， the optimization pump pressurization value is 12.9MPa and its efficiency is 26.9% under low flowrate conditions， where the derivation are 3.5% and 2.6%.