瑞利散射法研究超声喷流二氧化碳团簇尺度轴向分布

摘要

针对特定尺度的小锥喷嘴,用瑞利散射方法研究了超声喷流二氧化碳团簇的瑞利散射信号S和团簇尺度N的轴向分布.实验发现,散射信号强度的对数ln(S)随着轴向距离Z的平方根的增大线性减小,团簇尺度最大位置出现在距喷嘴轴向距离4 mm附近,在背压6-17bar范围内散射信号S与背压P满足S∝P3.6-4.2,测量到最大的团簇约为1.6×104分子/团簇.%The axial distribution of carbon dioxide clusters in supersonic gas jet was studied by Rayleigh Scattering method. It is found that the logarithm of scattering signal In(S) decreases linearly with the square root of Z and the position of 4 mm rather than the position nearest the nozzle has the maximum average cluster size. The scattering signal intensity exhibits a power scaling on the backing pressure ranging from 6 to 17 bar , and the power varies from 3.6 to 4.2. The axial cluster size was estimated and the maximum size was found to be 16 000 molecules/cluster.