Experimental techniques for measurements of vorticity and strain rates in compressible turbulence interactions with shock or expansion waves

Abstract

The present work describes The development and validation of a custom-made hot-wire vorticity probe capable of measuring the time-dependent highly fluctuating three-dimensional velocity and vorticity vectors, and associated total temperature, in non-isothermal and inhomogeneous flows with reasonable spatial and temporal resolution. The probe has been used in interactions of compressible homogeneous and isotropic turbulence with shock waves, interactions of vortices with shock waves, and interactions of homogeneous and isotropic turbulence with expansion waves. These flows have been configured in a large-scale shock tube facility. The availability of these data allowed the computations of several terms appearing in the transport equation of vorticity, the full dissipation rate of the kinetic energy term, and full rate-of-strain tensor. An analysis of the uncertainties involved in these measurements suggests that they depend on the particular flow under consideration.