齿形襟翼结构尾缘轴流风机性能仿真研究  

Simulation Study on Aerodynamic Performance of Axial Flow Fan with Serrated Flaps Trailing Edge

作　　者：郑楠 叶学民[1] 杨天康 李春曦[1] ZHENG Nan;YE Xuemin;YANG Tiankang;LI Chunxi(School of Power,Energy and Mechanical Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003

出　　处：《动力工程学报》2022年第5期450-457,共8页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金资助项目(11602085)。

摘　　要：以某两级动叶可调轴流风机为例,采用大涡模拟(LES)对不同齿长的齿形襟翼结构下的风机性能、涡结构和气动噪声进行了计算,分析了其内流特征、噪声源分布和降噪机理。结果表明:齿形襟翼可有效提升风机性能,且全压增幅与齿长成反比;齿形襟翼风机全压效率最高点向大体积流量侧移动,运行高效区变宽;随着齿长的增加,齿形襟翼的静压均值呈现先减小后增大的趋势,其中方案4的静压均值较原风机下降402 Pa,高频降噪最为显著;齿形襟翼可降低湍流脉动强度,尾迹涡的大小和分布区域减小,同时前缘分离涡数量也减少;齿形襟翼尾缘处产生了2对反向对称涡,其相互作用强烈,能量耗散加快,是齿形襟翼结构尾缘能降噪的主要原因。Taking a two-stage variable pitch axial flow fan as an example, the fan performance, vortex structure and aerodynamic noise were investigated for serrated flaps with different tooth lengths by large eddy simulation(LES), so as to analyze its internal flow characteristics, noise source distribution and noise reduction mechanism. Results show that the serrated flaps can effectively improve the fan performance, and the increase of total pressure is inversely proportional to the tooth length. The maximum efficiency point of the fan with serrated flaps would move to large flow rate side, and the high operation efficiency area becomes wider. With the increase of tooth length, the average static pressure of serrated flaps decreases first and then increases, and the average static pressure of case 4 decreases by 402 Pa compared with the original fan, therefore, the reduction of its high-frequency noise is the most significant. The utilization of serrated flaps can reduce the turbulence fluctuation intensity, the size and distribution area of wake vortices decrease, meanwhile, the number of leading-edge separation vortices decrease. Two pairs of antisymmetric vortices with opposite rotation directions appear at the trailing edge of the serrated flaps, leading to strong interaction between the two and fast energy dissipation, which is the main reason for the noise reduction.

关 键 词：动叶可调轴流风机 齿形襟翼 风机性能 噪声源分布 降噪机理 

分 类 号：TK83[动力工程及工程热物理—流体机械及工程]