湍流模型对高压比离心压缩机气动性能及流场结构影响的数值研究

Simulation Research of Effects of Turblence Model on the Aerody namic Performance and Flow Field Structure in High-press Ratio Centrifugal Compressor

为研究不同湍流模型对压缩机总体性能及内部流场数值模拟结果的影响,本文采用3个高雷诺数湍流模型和1个低雷诺数湍流模型对Krain实验研究的离心叶轮和等面积无叶扩压器进行三维定常流场计算,并与相应的实验结果进行对比。研究结果表明,4种湍流模型的数值模拟结果与实验结果均存在差异,这一差异与流量和转速有关。在高转速、小流量工况下,湍流模型对数值模拟结果的影响更为显著。数值模拟预测到的失速流量均与实验值差别较大。而从流场和总体性能两方面来看,与高雷诺数湍流模型相比,低雷诺数湍流模型的模拟精度更高,在设计工况附近区域,数值模拟的效率与实验符合良好。

In order to study the effects of different turbulence models on the predicted overall performance and flow field in the compressor, the 3D steady flow simulations were carried out on the Krain impeller and a vaneless diffuser of constant area by using three different high Reynolds number turbulence models and one low Reynolds number turbulence model. The numerical results were compared with the corresponding experimental results. The results show that, the numerical results of the four turbulence models don’t agree fully well with the experimental results,＆amp;nbsp;and the differences among them vary with both the mass flowrate and the rotation speed. The impacts of turbulence models on numerical results behave more significantly at the high-speed and low-flowrate operating points. The predicted stall points all departure from the experimental results. In terms of both the flow field and overall performance, the low Reynolds number turbulence model provides more accurate results than the high Reynolds number turbulence models do. Near the design operating condition, the predicted efficiencies by the numerical simulations are in good agreement with the experiment tested results.