使用莫尔条纹法测量气流密度

Density masurements of air jets by means of moire schlieren method

把莫尔条纹应用于对称的和非对称的流场，测出了从喷嘴喷出的不完全膨胀气流的密度分布。气流的内部密度分布通过使用数字表示的转化方法转变成了莫尔条纹图像数据，这些莫尔条纹图像数据表明了同种光在穿过气流时将会发生折射。这一现象可以通过改变气体喷口的压力比来完成并观察到。实验表明：不同形状的喷嘴喷出的气流密度分布各不相同，而且复杂程度也不同，但沿着喷嘴气流轴的气流密度变化大致相似。

Using the Moire schlieren method for symmetric and asymmetric flow fields, density distributions of underexpend free jets of air from nozzles have been measured. Experimental Moire image data of the flows, which shows integrated light deflection across the flow, were converted to an internal density distribution by the numerical inverting method, this appearance was observed by changing the pressure ratio across the nozzles. The experiment was found that the density profiles measured in the expanded free jets from different nozzles are entirely different, and complex degrees is varying, the density variations along the flow axis for nozzles were very similar to each other.