带涡流发生器射流齿形喷嘴湍流时空结构与气动声学研究

An active control technique of fluidic chevron jet noise with vortex generator is used to reduce the aero-engine exhaust noise. The turbulent structure of fluidic chevron injected vortices mixing with jet shear layers and its relation with the radiated noise in the close and far field of the nozzle is analyzed via experimental measurements. The turbulent structure is measured by time resolved particle imaging velocimetry(TR-PIV) and hot wire anemometer,the flow steadiness together with mode and interaction is analyzed with the advanced processing methods POD and DMD. The close field acoustic characteristics of fluidic chevron jet nozzle is measured by Microphone array, and its relationship with the flow is analyzed. At the same time, the far field noise radiation of the jet together with its directivity is measured and analyzed.Based on vortex sound theory the CFD simulation results of fluidic chevoron nozzle is re-analyzed to achieve the relation between vortex flow and aeroacoustic. On the other hand the acoustic analogy method is used to predict the far field noise generated by fluidic chevron nozzle. Based on turbluent structure of flow field and near-field acoustical holograghy, interaction between flow field and aeroacoustic is analyzed and the system is built.

采用带涡流发生器的射流齿形喷射噪声主动控制技术，降低航空发动机排气噪声。通过实验测量的方法，分析带射流齿形喷嘴其微射流注入涡流与喷嘴射流剪切层掺混形成的复杂湍流结构及其与喷嘴辐射近远场噪声的关联。采用高时空分辨粒子图像测速技术（TR-PIV）和热线测量方法，测量射流齿形喷嘴湍流结构，利用本征正交分解和动态模式分解等先进处理方法分析流动稳定性,模态分布和流场相干结构。采用麦克风阵列方式测量并分析射流齿形喷嘴的近场声学特性及其与流动关联。同时，测量并分析了喷射的远场声辐射及指向性特点。基于涡声理论对射流齿形喷嘴的数值模拟结果进行分析，采用声类比方法预测射流齿形喷嘴的声辐射。通过湍流时空结构与近场声全息方法,建立流声耦合分析系统.

采用带涡流发生器的射流齿形喷射噪声主动控制技术，降低航空发动机排气噪声。通过实验测量的方法，分析带射流齿形喷嘴其微射流注入涡流与喷嘴射流剪切层掺混形成的复杂湍流结构及其与喷嘴辐射近远场噪声的关联。采用高时空分辨粒子图像测速技术（TR-PIV）和热线测量方法，测量射流齿形喷嘴湍流结构，利用本征正交分解和动态模式分解等先进处理方法分析流动稳定性,模态分布和流场相干结构。采用麦克风阵列方式测量并分析射流齿形喷嘴的近场声学特性及其与流动关联。同时，测量并分析了喷射的远场声辐射及指向性特点。基于涡声理论对射流齿形喷嘴的数值模拟结果进行分析，采用声类比方法预测射流齿形喷嘴的声辐射。通过湍流时空结构与近场声全息方法,建立流声耦合分析系统.