Abstract:

As a variant of centrifugal pump, fuel VCP shows good application prospects in aero engines. The vapor core generating in impeller region had great influences on operation status and performance of VCP. Unsteady numerical simulation of VCP was presented herein based on RNG (renormalization group) κ-ε turbulence model and vapor-liquid two-phase cavitation model. Effects of inlet throttle opening and outlet load on vapor core region were studied. In order to verify the reliability of numerical results, basic characteristics of a prototype pump were tested. Results show that fuel vaporization inside the pump occurs at the impeller inlet. The vapor core region gradually expands with the decreasing outlet pressure. When expanding to the blade region, liquid fuel flows into the volute from the pressure side of blade. Other conditions being unchanged, vapor core region rapidly expands when reducing the throttle opening. Efficiency of the VCP is less than 20% at 2mm throttle opening. The simulation and test errors are within 10%.

Key words: vapor core pump(VCP), vapor-liquid two-phase, inlet throttle, numerical simulation

摘要：

作为离心泵的一种演变泵型，燃油汽心泵在航空发动机中应用前景良好，叶轮区形成的汽心对泵的工作状态和性能影响较大。基于RNG κ-ε湍流模型对汽心泵内流场进行了非定常汽液两相数值模拟，研究了进口节流活门开度与出口负载对汽心区域的影响规律。为验证数值模拟结果的精度，利用汽心泵样机开展了基本特性试验。结果表明，汽心泵内燃油汽化发生于叶轮进口端;汽心区域随出口负载减小逐渐扩张。扩张至叶片区后，燃油全部从叶片压力面一侧流道进入蜗室;其他工况不变时汽心区随节流活门开度减小而迅速扩张，2mm开度时泵的效率最低可降至20%以下。数值模拟与样机试验误差基本在10%以内。

关键词: 汽心泵, 汽液两相, 进口节流活门;数值模拟