斜流叶轮轴向蜗壳内流匹配分析

Numerical Analysis on the Internal Flow Matching of Diagonal Rotor and Axial Volute

斜流风机采用轴向入口方式的蜗壳设计使机构更紧凑。考虑蜗壳与斜流叶轮整体匹配设计中内流增效减损机制,按照气体自由流动轨迹设计蜗壳型线;通过内流匹配分析,比较了流叶轮对称和不对称两种轴向蜗壳入口方式,不对称蜗壳静压分布较好;单向涡流束取代了对称蜗壳中的双向涡流,从而避免了由于双向涡流引起的中间层的分离,减少了耗散损失,提高了外特性性能。在此基础上设计了几种轴向非对称蜗壳,比较了小直径轴向内蜗壳斜流风机采用无叶扩压器和有叶扩压器两种配置方案的内流场。指出了斜流叶轮设置导向叶片扩压器有利于提高风机性能,因此在斜流风机中推荐使用叶片扩压器。

Using the Axial inlet volute in the diagonal fan make the structure more compact than using the other volutes. Considering the mechanism which the overall matching of the diagonal rotor and the volute increase efficiency and decrease loss, the volute model lines are designed according to the free flowing track. Through the internal flow matching analysis, the symmetry air-inlet style and the asymmetry air-inlet style of the diagonal rotor to the volute are compared. It is indicated that the asymmetry style has a better static pressure distribution in the volute, and avoids the intermediate layer separation due to the double direction vortex, reduces the dissipation loss, and improve external characteristic, as the single vortex in the asymmetry style replaces the double direction vortex in the symmetry style. On the base, a few axial asymmetry volutes are designed. The thesis compares the vaneless diffuser with the vane diffuser, and indicates that the vane diffuser is propitious to improve the fan performance.