弯曲扩压通道内脉冲射流位置影响的POD分析

Proper Orthogonal Decomposition Analysis of Pulsed Jet location in Divergent Curved Channels

基于一种弯曲扩压通道在不同射流位置状态下,开展了脉冲射流控制的试验及数值模拟研究,引入本征正交分解(Proper Orthogonal Decomposition,POD)技术以模态的方式完成了脉冲射流控制效果的分析。结果表明:随着射流位置逐渐由上游靠近分离点,各个射流位置最佳射流频率逐渐接近于通道内分离涡主频,分离点附近及下游位置最佳射流频率与通道内分离涡主频保持一致;最佳射流频率下,随着射流位置逐渐接近于分离点,分离涡模态能量在脉冲射流的作用下向平均流模态转移的比例逐渐增加,向高阶模态能量转移的比例逐渐减小;分离点位置对应着最佳射流位置,该状态下POD各阶模态能量均向平均流模态进行转移,脉冲射流控制效果最为明显。

Based on a divergent curved channels experimental mode,the experimental and numerical simulation in different pulsed control location states has been presented,and the proper orthogonal decomposition(POD) method is introduced to analyze the unsteady control effect.Results show:with the approach of jet location from the upstream to the separation point,the best frequency is close to the frequency of domain separation vortex;and when the jet location is near or behind the separation point,the best frequency is consistent with the frequency of domain separation vortex.In the best unsteady control frequency states,the energy of separation mode will transfer to the averaged mode or the high modes;when the jet location is close to the separation point,the energy transfer ratio to the averaged mode is increased,and the energy ratio to the high modes is decreased.The best location of pulsed jet is near the separation point,and energy of each mode will transfer to the averaged mode,the unsteady pulsed control effect is more obvious.