基于Kriging代理模型的单边膨胀喷管尾缘切角优化

Optimization of trailing edge angles of single expansion ramp nozzle based on Kriging method

在设计点落压比25和非设计点落压比15条件下,对单边膨胀喷管(SERN)不同尾缘切角模型进行了三维数值模拟,并采用Kriging代理模型以SERN轴向推力系数为目标,对尾缘切角进行多目标优化。研究结果表明:尾缘切角会影响SERN后气体的膨胀,增强流动的三维效应,恰当的尾缘切角会使SERN后气体更充分膨胀,有利于提高SERN的轴向推力系数,改善SERN的性能;通过优化,SERN的轴向推力系数由0.94达到了0.975以上,比优化之前提高了约5%,基于Kriging代理模型的SERN优化方法是有效的。

Based on three-dimensional numerical simulation,different trailing edge angles of single expansion ramp nozzle（SERN）were studied under the condition of nozzle pressure ratio of 25 as the design point,and nozzle pressure ratio of 15 as the undesign point.The trailing edge angles were optimized to get a higher axial thrust coefficient under the nozzle pressure ratio of both 25 and 15 by the Kriging method.Results showed that the trailing edge angles made plume expanding better and the three-dimensional effect of fluid was enhanced.This was propitious to improve the axial thrust coefficient.What＇s more,within the design range,the axial thrust coefficient increased from 0.94 to 0.975,about 5% after optimization.So the optimization based on Kriging method is effective.