Interferometric Techniques and Data Evaluation Methods for the UTIAS 10 cm x 18 cm Hypervelocity Shock Tube.

摘要

The UTIAS 10 cm x 18 cm Hypervelocity Shock Tube has been used in recent years to study ionizing shock structures, flat-plate and side-wall boundary layers and nonstationary oblique shock-wave diffractions over compression corners. These phenomena were recorded using a 23-cm dia field of view Mach-Zehnder interferometer equipped with a giant-pulse dual-frequency ruby laser. In order to extract the maximum amount of data in these complex flows a digital evaluation method was employed. For this technique a new approach to the theory of interference was developed. In this approach the spatial coordinates (x,y) of the various lines of interference (fringes) on the interferograms are put into digital form, thereby making a computer analysis possible. The experimental technique and instrumentation associated with the various measurements involved in research using the UTIAS 10 cm x 18 cm Hypervelocity Shock Tube are described. Finally the maximum possible absolute and relative errors associated with these measurements are calculated for four different gases (argon, krypton, oxygen and nitrogen) which are usually used as test gases.