Further Validation of a CFD Code for Calculating the Performance of Two-Stage Light Gas Guns

Earlier validations of a higher-order Godunov code for modeling the performance of two-stage light gas guns are reviewed. These validation comparisons were made between code predictions and experimental data from the NASA Ames 1.5" and 0.28" guns and covered muzzle velocities of 6.5 to 7.2 km/s. In the present report, five more series of code validation comparisons involving experimental data from the Ames 0.22" (1.28" pump tube diameter), 0.28", 0.50", 1.00" and 1.50" guns are presented. The total muzzle velocity range of the validation data presented herein is 3 to 11.3 km/s. The agreement between the experimental data and CFD results is judged to be very good. Muzzle velocities were predicted within 0.35 km/s for 74% of the cases studied with maximum differences being 0.5 km/s and for 4 out of 50 cases, 0.5 - 0.7 km/s.