基于前缘锯齿形叶片的多翼离心风机数值分析与实验研究
Numerical Analysis and Experimental Research of Multi-blade Centrifugal Fan based on Leading-edge Serrated Blade

为减少叶片附近的涡流，降低多翼离心风机流场的流动损失和气动噪声，设计了一种具有锯齿形前缘的空调器用离心风机叶片。与常见改型叶片不同，并未从整个叶片宽度方向进行改进，仅从叶轮前盘沿叶片前缘的1/3叶轮宽度处开设锯齿结构。基于几何相似原理和FLUENT软件，对计算得出的不同锯齿结构进行数值模拟，结果显示：锯齿结构主要对聚集在靠近前盘的涡流进行破坏，蜗舌、叶片后缘和叶间涡流较原型叶片也明显减少，且降低了基频噪声。结果表明：在不同转速下，前缘锯齿形叶片多翼离心风机的整机风量较原型机基本不变，噪声值降低0.9~1.2 dB(A)，输入功率降低2.75~3.55 W。说明具有锯齿形前缘结构的叶片，不仅能优化风机的风道性能，还能起到节能降噪的作用。
A serrated leading-edge blade for a multi-blade fan of an air conditioner is designed. The main objective is to reduce the vortex near the blade, thus reducing the flow loss and aerodynamic noise of the flow field of the multi-blade fan. Whereas it is different from the common reformed blade, no improvement in the width of the whole blade but a front disk along the leading edge by one-third of the impeller width was made. The various serrated structures were simulated based on the geometric-similarity principle using the FLUENT software. The simulated results show that the serrated structures destroyed the accumulated vortex close to the front disk. In contrast to the prototype blade, all vortices in the volute tongue, trailing edge, and internal leaves were obviously decreased with the use of the serrated blade. Meanwhile, the fundamental frequency noise was decreased. The experimental data indicated that the air volume of the leading-edge serrated blade of the centrifugal fan varied a little under different speeds. The noise and input power were decreased by 0.9–1.2 dB (A) and 2.75–3.55 W, respectively. Thus, the serrated leading-edge blade can not only benefit the air-duct performance but also play a role in energy savings and noise reduction