平地机冷却风扇的改进与信噪比分析

Improvement and signal-to-noise ratio analysis of cooling fan for grader

为提升冷却风扇性能,改善空气流动状态,结合国内某款平地机建立其冷却风扇三维模型,在虚拟风道内,利用CFD数值仿真方法对其进行分析,并将仿真结果与实验数据进行对比;利用变环量设计法对原风扇进行重新设计,在相同边界条件下对其进行仿真,对比两风扇仿真结果;分析新风扇结构参数对其性能的影响,并通过正交试验对不同结构参数组合下信噪比进行分析。结果表明:原风扇实验值与仿真值在静压、静压效率上的最大误差分别为8.35%,2.34%,均在可接受范围内,验证了仿真方法的正确性;在大部分流量区间,新风扇的静压、静压效率均大于原风扇,表明改进有效;在信噪比分析中,轮毂比对冷却风扇综合性能影响的贡献率为42.25%,叶片数的为35.98%,叶尖安装角的为11.07%,前弯角的为10.7%。研究结果可为冷却风扇的设计与改进提供一定的参考。

In order to improve the performance of the cooling fan and air flow,combined with a domestic grader,a 3D model of the cooling fan was established,and the CFD numerical simulation method was used to analyze its performance in a virtual wind tunnel,whose results were compared with the experimental data.The original fan was redesigned with the variable circulation design method,and the same simulation method was used for the analysis on the new fan under the same boundary conditions.Based on the comparison between both simulation results,the influence of structural parameters on performance of cooling fan was analyzed,and the signal-to-noise ratio（SNR）under different combinations of structural parameters was analyzed with orthogonal test.The results showed that the maximum error between the experimental data and the simulation value of static pressure and static pressure efficiency for the original fan were8.35% and 2.34%,respectively,which verified the correctness of the CFD simulation.Over the flow range,the static pressure and static pressure efficiency of the new fan were higher than that of the original one,which indicated the improve was effective.In the SNR analysis,the contribution rate of wheel hub to the comprehensive performance of cooling fan was 42.25%,and that of blade number,blade tip angle and front bend angle blade number were 35.98%,11.07%,and10.7%,respectively.The results can provide a reference for the design and improvement of cooling fans.