【摘要】 该文采用旋涡强度方法对冲击射流涡结构进行了深入研究。首先将粒子成像测速技术(P IV)测量得到的原始流场图片进行相应处理得到原始速度场,再利用b ior5.5双正交小波分析得到消除高频噪声的流场结构;然后对此进行涡量和旋涡强度计算,得到相应的涡量场和旋涡强度场。与涡量方法相比,因旋涡强度方法排除了剪切作用的影响,故可以更有效地分析流场中的涡结构。进而得到了冲击射流中的旋涡强度随压比、冲击距离、喷嘴唇厚等参数的变化规律。更多还原

【Abstract】 The swirling strength method was used to investigate the vortex structure of an impinging jet.The initial jet flow field was obtained from particle image velocimetry(PIV) measurements.Then a bior5.5 biorthogonal wavelet analysis was used to obtain the flow field structure without high-frequency noise.The vorticity field and swirling strength field were then calculated from the flow structure.Since the swirling strength method eliminates the effect of the shear,it is a better method to analyze the vortex structure than the vorticity method.The swirling strength variations can then be obtained as a function of the impinging pressure ratio,impinging distance,nozzle-lip thickness,etc.更多还原