小型前弯离心风机叶轮参数优化

Optimization for Impeller Parameters of Small Forward Curved Centrifugal Fan

为了提高小型前弯离心风机的气动性能,以汽车座椅通风用离心风机为研究对象,采用数值模拟与正交试验相结合的方法,研究叶片数、叶片出口角、叶片进口角以及叶片厚度对离心风机气动性能的影响.基于小风量风机性能实验台,验证数值模拟结果的正确性.选取三水平正交表L_(9)(3^(4))进行此次试验,建立了9种不同参数组合下的叶轮模型,以最大静压为优化目标,采用计算流体动力学方法,得到了最佳离心风机参数组合.对优化前、后离心风机内部流场的压力与速度分布进行了对比分析.由正交试验结果分析可知,各参数对离心风机最大静压影响的主次顺序为叶片出口角、叶片进口角、叶片数和叶片厚度;达到最大静压的参数组合为:叶片数55,叶片进口角95°,叶片出口角125°,叶片厚度0.8 mm.优化后离心风机的无因次特性曲线优于原有风机,在高效率区域静压可提高3.78%~10.67%,具有更好的气动性能.对比优化前、后离心风机内部流场的压力与速度分布可知,优化后的离心风机内部流场分布更加均匀,在叶轮进口处低压区的压力更低,速度更大,更有利于气流的进入.

To improve the aerodynamic performance of a small forward curved centrifugal fan,the centrifugal fan used for car seat ventilation was taken as the research object in this paper.The effects of the number of blades,the blade outlet angle,the blade inlet angle,and the blade thickness on the aerodynamic performance of the centrifugal fan were studied by means of combining numerical simulation and an orthogonal experiment.The experiment used a small air volume fan performance test bench to validate the numerical simulation results.Three-level orthogonal table L_(9)(3^(4))was selected to arrange the test,and impeller models with nine different parameter combinations were es⁃tablished.The optimal centrifugal fan parameter combinations were obtained by using the computational fluid dynam⁃ics method with maximum static pressure as the optimization objective.In addition,the pressure and velocity distribution in the centrifugal fan before and after optimization were compared and analyzed.According to the direct analysis of the orthogonal test results,it can be seen that the influence of each parameter on the maximum static pressure of the centrifugal fan is in the order of the blade outlet angle,the blade inlet angle,the number of blades and the blade thickness.In addition,the maximum static pressure can be achieved by the following parameters:the number of blades of 55,the blade inlet angle of 95°,the blade outlet angle of 125°,and the blade thickness of 0.8 mm.The di⁃mensionless characteristic curve of the optimized fan is better than that of the original fan,and the static pressure can be increased by 3.78%~10.67%in a high-efficiency area.Compared with the pressure and velocity distribution of the flow field inside the centrifugal fan before and after optimization,the distribution of the flow field inside the opti⁃mized centrifugal fan is more uniform,the pressure in the low-pressure area at the impeller inlet is lower,and the ve⁃locity is higher,which is more conducive to the flow into the centrifugal fan.