Holographic interference measurement of the hypersonic flow field

A holographic interferometry system is developed to improve flow field visualization and measurement. The test objects are free-flight models, which have axis-symmetric shape; these models fly at the hypervelocity of M = 2.25 to M = 15 in normal static atmosphere. They are shot into a free-flight ballistic range (FFBR) that is 200 m in length and has 30 observation windows. Finite and infinite holograms of the models are taken and reconstructed. Moreover, the quantitative measuring results of the density distribution and the computation interferogram of the flow field are completed. The separation between the sphere model and the bow shock wave is measured.