高速诱导轮三维非定常湍流数值模拟

基于N—S方程和滑移网格技术，利用FLUENT软件对诱导轮内部流场进行了全三维非定常湍流数值模拟，获得了诱导轮内部的速度分布、静压分布以及流体压力脉动特征等重要的流动信息．描述了诱导轮进口及轮缘间隙处的回流现象，解释了回流现象发生的原因，即轮缘处叶片压力面和吸力面存在压差；分析了回流引起的进口低压区对诱导轮汽蚀性能恶化的过程；采用快速傅立叶变换处理监测点的压力脉动数据，发现流体压力脉动中的主导频率成分约为转频的Z次谐波，所以可避免流体脉动诱发的机械谐振．模拟结果为高速诱导轮的改进设计提供了一定的理论依据．

Numerical simulation of 3D unsteady turbulent flow in high-speed inducer

Based on the N - S equations and the sliding mesh technology, the 3 D unsteady flow within a high-speed inducer was simulated by FLUENT. The important information about the internal velocity distribution, static pressure distribution and fluctuant pressure of flow in inducer were obtained. Backflow phenomena in the inlet of inducer and the flange clearance were described. The cause of pressure difference between suction surface and press surface was explained. The deterioration process of inlet low pressure area caused by backflow on cavitations characteristics of inducer was analyzed. Fast Fourier Transform was used to deal with the pressure pulsation data of measuring points. The dominant frequency of fluid pressure pulsation is equal to Z degree harmonic wave of rotational frequency, so the mechanical resonance caused by fluid pulsation can be avoided. The results of numerical simulation provide theoretical basis for improving the design of high-speed inducer.