预旋喷嘴对预旋系统温降特性的数值研究

Numerical Research on Influences of Pre-Swirl Nozzle on Temperature Reduction Characteristic of Pre-Swirl System

预旋喷嘴的结构参数主要有预旋喷嘴面积、预旋喷嘴角度和预旋喷嘴的轴向长度。通过试验验证了湍流模型,对存在掺混进气的盖板预旋系统的温降特性进行数值模拟。在其他条件一定的情况下,分析了预旋喷嘴面积、喷嘴角度和喷嘴轴向长度对系统温降的影响。研究结果表明:随着预旋喷嘴面积增加,喷嘴内压力损失降低,进入盘腔内的质量流量增大,盘腔内的静温降低,有利于增加预旋温降效果;随着预旋喷嘴角度的增加,降低了气流流出喷嘴时的周向速度,预旋温降效果变差;预旋系统温降随预旋喷嘴轴向长度的增加先增加后降低。

The structure parameters of pre-swirl nozzle include pre-swirl nozzle area,pre-swirl angle and the axial length of pre-swirl nozzles. The selected turbulence model was valid by experiments and the numerical simulation was conducted to investigate the temperature reduction of a cover-plate preswirl system with the seal leakage flow. Under the certain conditions,the influence of temperature reduction was carried out by changing pre-swirl nozzle area,pre-swirl angle and the axial length of preswirl nozzles. The results show that with the increase of the pre-swirl nozzle area,the pressure loss decreases in the nozzle,the mass flow rate increased and static temperature reduces,which is helpful to the temperature reduction. With the increasing of the pre-swirl nozzle angle,circumferential veloci-ty is smaller and the temperature reduction is lower. Temperature reduction takes on an up-down tendency with the increasing of the axial length of pre-swirl nozzles.