中文摘要：

本文提出采用一种新型的不等距蜗舌（这里统称为斜蜗舌）在提高风机的外特性性能的同时，相对降低噪声。通过试验与数值模拟，比较直叶片式、斜叶片式贯流风机分别用直蜗舌和斜蜗舌时内流、外特性及噪声频谱。采用三维Navier—Stokes方程和k—ε两方程湍流模型对内部流场进行数值分析，发现与采用常规蜗舌的贯流风机不同的是斜蜗舌贯流风机偏心涡位置随着蜗舌间隙的变化而发生改变。本文旨在探讨斜蜗舌对贯流风机内流的影响及降噪的机制。

英文摘要：

A new variable tip clearance tongue is used in the cross-flow fan of the split type room airconditioner. Experimental results show that the fan using the new variable tip clearance tongue has a better aerodynamic performance, and has a better noise characteristic. In this paper, the fan using the new variable tip clearance tongue with the skew blades along the span, the fan using the conventional tongue with the skew blades, and the fan using the conventional tongue with the straight blades along the span are contrasted in internal flow, aerodynamic performance and noise characteristics. Internal flow characteristics simulated numerically based on three-dimensional Navier-Stokes equations coupled with k - ε Turbulence model show the movement of eccentric vortex along the span with the variable tip clearance which is different with the fan using the conventional tongue. The research discusses the mechanism that the variable tip clearance tongue affects internal flow and reduces noise of the fan.