Comparison of molecular tagging velocimetry data and direct simulation Monte Carlo simulations in supersonic micro jet flows

We present results of a combined experimental computational study of free jet flow produced by a 1 mm (height) x 5 mm (span) nominally Mach 2 supersonic jet. Two-dimensional maps of u(x), the component of velocity parallel to the principal flow axis, are obtained experimentally, by acetone molecular tagging velocimetry (MTV), and computationally, by the direct simulation Monte Carlo (DSMC) method, at a stagnation pressure and temperature of 10 torr and 300 K, respectively. In all cases, direct comparison of the experimental data and the predictions from DSMC showed excellent agreement, with only minor deviations which, in most cases, can be ascribed to either the inherent uncertainty in the MTV or to small uncertainties in the measured wall pressures. (Author)