采用仿？^翼叶片降低空调用离心风机 气动噪声的研究
A Study on Noise Reduction of Centrifugal Fan in Air Conditioner by Using the Bionic Blade Inspired by the Owl Wing

基于逆向工程设计方法,提取具有优良气动性能和低噪声特性的长耳？^翅膀展向40％截面位置处的翼型进行仿生重构,并将其应用于窗式空调用离心风机叶片的叶型改进中。采用数值计算方法研究了仿？^翼翼型叶片4种不同中弧线分布方式的降噪效果,对最优设计风机的气动性能和噪声进行了试验验证。与原型相比,仿生翼型叶片按照单圆弧中弧线分布设计的离心风机降噪效果最好,在风量基本保持不变的同时风机噪声下降了1？？3 dB。风机内部流动及其噪声特性的数值模拟结果表明:仿？^翼叶片的应用可减少叶轮流道内的低速分离区域,有效抑制通道内旋涡流的产生和发展,同时减弱叶轮与蜗舌间周期性的非定常相互作用,降低叶片前缘区域和蜗舌区域的压力脉动,从而有效降低空调用离心风机产生的气动噪声。
The airfoil in the position of 40％ spanwise of the long？？eared owl wing which has excellent aerodynamic performance and low noise characteristics is extracted to reconstruct the bionic blades based on the reverse engineering design method. Then these designed bionic blades are applied to improve the aerodynamic performance and reduce the aerodynamic noise of centrifugal fan in window air conditioner. Numerical simulation and experimental study are conducted to investigate the effects of four different distributions of medial camber line of the bionic blades on the aerodynamic performance. The validity of the numerical model and the method is confirmed through experimental measurements. When the bionic blade inspired by the long？？eared owl wing airfoil is distributed by mono？？arc medial camber line, the noise of the centrifugal fan reduces by 1？？3 dB while the flow rate is basically unchanged. The numerical results of the internal flow and noise characteristics on the centrifugal fan show that when the optimal bionic blade is used, the low？？speed separation region in the impeller reduces and the generation and development of the vortex is suppressed effectively. At the same time, the periodic unsteady interaction between the impeller and the volute tongue and the amplitude of pressure fluctuation in the region of blade leading edge and volute tongue were weakened. This is also one of the reasons why the aerodynamic noise of the centrifugal fan in the air conditioner is reduced when the bionic blade inspired by the long？？eared owl wing is used