预旋喷嘴径向角度对预旋特性影响的数值研究

为了降低低位进气预旋流路的气动损失，针对带有不同径向角度（0°~30°）预旋喷嘴的预旋系统进行了数值仿真，并对流动特性、温降特性和比熵增特性进行了分析。结果表明:随着预旋喷嘴径向角度的增大，预旋系统无量纲温降先增大后减小，流动阻力减小，预旋系统的流量随之增大。旋转雷诺数为2.3×107时，预旋喷嘴带径向角度的预旋系统无量纲温降比传统喷嘴最大可提高18.3%，存在某一角度使预旋温降特性达到最好。预旋系统内的耗散主要发生在预旋腔和共转盘腔内，径向角度为10°时其比熵增变化量分别占整个预旋系统总体比熵增的42.4%和30.2%；合理设计预旋喷嘴的径向角度，能改善预旋腔内气流的流动效果，并且可以减少整个预旋系统的不可逆损失。 

Numerical study on influence of pre-swirl nozzle radial angles on pre-swirl characteristic

To reduce the aerodynamic loss in a low position pre-swirl system, numerical simulations were carried out to study the flow characteristics, temperature drop and specific entropy increment for pre-swirl system with nozzles radial angles from 0° to 30°. The results showed that non-dimensional temperature drop increased firstly and then decreased, and flow resistance reduced with the increasing pre-swirl nozzle radial angle bringing about the increase of mass flow rate. The non-dimensional temperature drop of pre-swirl system nozzles with radial angle most increased 18.3% than traditional nozzles when rotational Reynolds number was 2.3×107, and there was a certain angle that could lead to the best characteristics of temperature drop. The dissipative loss of the pre-swirl system mainly occurred in the pre-swirl cavity and the rotating cavity, making up 42.4% and 30.2% of the total specific entropy increment respectively when nozzles radial angle was 10°. It could improve the flow effects in pre-swirl cavity and reduce the loss of pre-swirl system if the nozzles radial angle was designed properly.