集流器结构对多翼离心风机气动性能的影响
Effects of Inlet Nozzle Structure on the Aerodynamic Performance of Multi？？Blade Centrifugal Fan

针对多翼离心风机的集流器,采用计算流体力学(CFD)方法和实验测量方法研究了结构对吸油烟机用多翼离心风机气动性能的影响。首先,通过CFD方法对吸油烟机用多翼离心风机的原型机进行了多工况数值模拟,获得流量？惭沽π阅芮？线,并将数值模拟结果与实验测量结果进行比较,验证了本文模型的有效性。然后,通过改变集流器出口直径do与集流器到叶轮轴向间隙δ来确定集流器最佳结构参数,达到提高风机气动性能的目的。与原型风机相比,采用经过参数优化的集流器,风机的气动性能得到提升。优化前后多翼离心风机内部流场的分析结果表明:集流器结构参数的优化,使得多翼离心风机在整个工况范围内的气动性能都得到了提升;但是,随着集流器与叶轮之间轴向间隙的增大,风机气动性能的变化呈非线性;当do=206 mm、δ=6 mm时,风机的风量达到最大。实验测量结果表明:所用集流器的多翼离心风机的最大风量增加了1？？0 m3/min,最大静压提升了25 Pa。数值和实验研究工作对多翼离心风机性能改进具有理论意义和实际应用价值。
The effects of inlet nozzle structure and its parameters on the aerodynamic performance of multi？？blade centrifugal fan were investigated numerically and experimentally. Numerical method was used to simulate the multi？？working conditions of the fan, and the flow rate？？pressure curve was obtained. By comparing the numerical simulation with the experimental results, the validity of the computational model and numerical method was testified. Then, by changing the outlet diameter of the inlet nozzle do and the clearance δ between inlet nozzle and impeller, the optimum structural parameters of the inlet nozzle could be determined to improve the aerodynamic performance of the fan. Analysis on the internal flow fields of the fan before and after optimization shows that the aerodynamic performance of the fan is improved in the whole operating range when the optimized inlet nozzle is used. However, with the increase of the axial gap between the inlet nozzle and the impeller, the change of the aerodynamic performance of the multi？？blade centrifugal fan is nonlinear. When do=206 mm and δ=6 mm, the maximum flow rate of the fan is obtained. Experimental results also show that the maximum flow rate and static pressure of the multi？？blade centrifugal fan are increased by 1？？0 m3/min and 25 Pa, respectively. This study may have a certain theoretical significance and practical application value for the performance improvement of multi？？blade centrifugal fans