离心风机整机三维数值仿真方法及分析

Three-Dimensional Numerical Emulation Method and Analysis of a Whole Centrifugal Fan

离心风机的性能特征与其内部流场结构是密切关联的,某些简化模型下对风机内某个部件或某个流道做的数值仿真并不能准确反映蜗壳与叶轮之间的相互作用。为了解其性能变化的根本原因,达到优化风机性能改善系统特性,需要对整机进行详细的流场结构分析。在软件Numeca的Fine/Turbo模块上,采用壁面函数法,对某离心风机在设计转速下不同工况点进行了数值仿真,与已有的试验数据对比,吻合较好,并准确反映了蜗壳与叶轮之间的相互作用,为风机的设计和性能优化提供了可信的理论依据。

There is close connection between centrifugal fan＇s performance characteristic and its internal flow field structure.It confirmed that the numerical emulation of some part or some flow channel in certain simplified model of a central fugal fan cannot reflect the interaction between volute and impeller accurately.In order to understand the reason why its performance changed,it needs to analysis the detailed flow field structure of the complete machine.This article carried on the numerical emulation uses of some centrifugal fan under the designed rotational speed at different operating point,using the Fine/Turbo module of commercial software Numeca and the wall surface function method.The result tallied well with the existing tentative data.On this basis,this article analysised the nonuniformity and dissymmetry of the flow field in the volute.The numerical emulation reflect the interaction between volute and impeller accurately,and it also provided credible theory for the design and performance optimization of a central fugal fan.