多翼离心风机双圆弧叶片的参数优化设计及气动性能分析

Parametric Optimization Design of Double-Circular Arc Blade Used in Multi-Blade Centrifugal Fan and Its Aerodynamic Analysis

为改善多翼离心风机气动性能和噪声特性,结合双圆弧叶片具有较高流道设计自由度的特点,本文以性能较优的单圆弧叶片多翼离心风机为基础,通过CFD与实验相结合的方法对双圆弧叶片进行全参数匹配优化设计。以0 Pa静压工况下风机风量为优化目标,采用Box-Behnken响应面实验设计方法对双圆弧叶片的进口角、出口角、内外径比、拱点圆直径以及中心角进行参数方案设计,获得了46组样本空间。通过对设计参数和样本结果进行二次回归拟合,得到了双圆弧叶片参数与风量的函数关系及最优参数组合。结果表明,进口角和出口角在所有主效应中对风量的影响灵敏度最高,而进口角-出口角以及内外径比-中心角在所有交互效应中对风量的影响灵敏度最高。通过CFD和FW-H声类比方法对风机的气动性能和声场进行数值计算,计算结果表明优化风机的风量较原型风机增加了118 m^(3)·h^(-1),相对提升9.7%。优化叶片能够有效抑制叶间流道内旋涡流的生成和发展,叶片的进、出口角与气流的进、出口流动冲角吻合度更高,有效减小了叶片前缘气流冲击产生的压力脉动以及尾迹流与蜗壳的非定常相互作用。实验结果表明,优化风机功率较原型机降低了4.7%,噪声下降了1.8 dB。

In order to improve the aerodynamic performance and noise characteristics of multi-blade centrifugal fan,combining with the characteristics of high degree of freedom in the design of inter-blade flow channel of double-arc blade and based on a single-arc blade multi-blade centrifugal fan with better performance,a full parameter matching optimization design of double-arc blade is carried out through the combination of CFD and experiments.Taking the air volume of the fan under 0 Pa static pressure condition as the optimization goal,the Box-Behnken response surface experimental design method is used to determine the inlet angle,outlet angle,inner to outer diameter ratio,arch point diameter and central angle for parameter design,and 46 sets of sample spaces are obtained.Through the quadratic regression fitting of the design parameters and the sample results,the functional relationship between the parameters of the double-arc blade and the air volume,as well as the optimal parameter combination,is obtained.The results show that the inlet angle and outlet angle have the highest sensitivity to the air volume in all main effects,while the inlet angle,the outlet angle,the inner diameter to outer diameter ratio and the central angle have the highest sensitivity to air volume in all interaction effects.The CFD and FW-H methods are used to calculate the aerodynamic performance and sound field characteristics of the optimized double-arc blade fan and the prototype fan.The results show that the air volume of the optimized fan increases by 118 m^(3)·h^(-1) compared to the prototype fan,with a relative increases of 9.7%.The optimized blade can effectively suppress the generation and development of vortex flow in the inter-blade flow channel.The inlet angle and outlet angle of the blade are more consistent with the inlet and outlet flow angles of the airflow,which effectively reduces the pressure pulsation caused by the impact of the blade leading edge and the unsteady interaction of wake flow and volute.The test results show that the power of the fan under the same air volume is reduced by 4.7%compared with the prototype,and the noise is reduced by 1.8 dB.