离心通风机蜗舌及出口流场的数值模拟分析

Analysis on Volute Tongue and Outlet Flow Field of Centrifugal Fan by Numerical Simulation

通过对离心通风机的变工况定常流动数值模拟,主要研究了蜗壳舌部及出口流场结构的演变规律,并分析了不同工况下所对应的风机特性变化实质,指出就蜗壳而言,其小流量工况时的"喉部"挤压现象、大流量时的出口流动漩涡及蜗舌回流现象,是影响风机整体特性及运行工况范围的主要因素之一;改善蜗舌及出口几何结构,可以有效提高风机的压头及运行效率。

In this paper, the constant state flowing in a centrifugal fan is described under the off - design condition by numerical simulation. In orde to reveal the changing regulation of the fan characteristics under the different operating conditions, the developing laws are analyzed on the structure of volute tongue and outlet flow field It is concluded that the 'throat' extruding phenomenon during the small flowrate operation the moving whirlpools at outlet field and back flowing phenomenon at volute tongue during the mass flowrate, which is one of the main factors to influence the whole structure and operation ranges of fan. It is indexed that improving the geometry structures of the volute and outlet shape could enhance the fan pressure and operation efficiency obviously.