横流式风机内部非定常流的数值计算

UNSTEADY FLOW ANALYSIS IN A CROSS-FLOW FAN WITH A CASING

提出了一种预测横流式风机内部流场的方法，适用于任意形状的叶片和涡壳。该方法假设流体无粘性，不可压缩，流动为二元流动，采用直接边界元法和离散旋涡法相结合的方法来计算风机的内部流场，同时考虑了涡室上部壁面边界层的影响。为了满足开尔文定理，叶片后缘处有尾涡放出，尾涡的运动用离散旋涡法计算。实际计算了两种不同涡壳的风机。

A numerical analysis method has been developed for the prediction of the flow in a cross-flow fan with a casing.The method has no simplifying assumptions regarding the geometryof both the impeller biades and the casing,Taking into consideration the effect of the bound-ary layer on the upper wall surface of the casing,the internal flow is analyzed using both thedirect boundary element method and the discrete vortex method by assuming that the flow istwo-dimensional,inviscid and incompressible,In order to satisfy Kelven's theorern,vorticityis shed at the trailingcdges of each impeller blade,then the discrete vortex method is used toapproximate the convection of the free vorticity.Results are given for the cross-flow fanwith two different configurations of the casing with an identical impeller.