微尺度离心叶轮间隙泄漏流动堵塞模型

通过理论分析结合数值模拟，开展了针对微尺度离心叶轮间隙泄漏流动堵塞模型的研究.结合微尺度旋转机械低雷诺数和高马赫数的工作条件，建立了考虑可压缩性和黏性损失的间隙泄漏流动堵塞模型.通过数值模拟分析了微尺度间隙泄漏流动特征及黏性在其中的作用，判定黏性作用对间隙泄漏流动的驱动作用不可忽略，黏性作用与压差作用对间隙泄漏流动的驱动作用效果相当.同时，黏性作用还会导致间隙泄漏流动的初始堵塞增大.采用某微尺度离心叶轮对间隙泄漏流动堵塞模型进行了验证，从数值计算结果中提取气动堵塞结果并与模型预测结果进行对比，表明改进的间隙泄漏流动堵塞模型能更准确地对间隙泄漏流动堵塞进行评估，在微尺度条件下具备更好的适用性. 

Model of tip clearance leakage flow blockage in micro-scale centrifugal impellers

The model of tip clearance leakage flow blockage in micro-scale centrifugal impellers was studied through theoretical analysis in combination with numerical simulations. Based on both low Reynolds number and high Mach number working condition of micro-scale rotating machinery, a model of tip clearance leakage flow blockage was established considering the compressibility and viscous loss. The features of micro-scale tip clearance leakage flow were analyzed and the viscous effect was explained with the help of numerical simulations. It is concluded that viscous effect is important in driving the tip clearance leakage flow, in agreement with differential pressure meanwhile resulting the increase of initial blockage of tip clearance flow. The verification of tip clearance leakage flow blockage model was carried out on a micro-scale centrifugal impeller. Tip clearance leakage flow blockage result extracted from numerical result was compared with model prediction results, and the result of improved tip clearance leakage flow blockage model shows more accurate evaluation and more suitable in micro-scale condition.