Performance evaluation of shock tube with helium and carbon dioxide using numerical simulation

Abstract

This work deals with the performance of the shock tube with helium and carbon dioxide as working fluids at different diaphragm pressure ratios using numerical simulation. A two-dimensional planar geometry of the shock tube is considered for the study. An inviscid time accurate model is developed to find the effects of diaphragm pressure ratios on the shock Mach number, temperature behind the incident and reflected shocks.. This numerical model is validated analytically as well as experimentally with air as working gas. Simulations were conducted for same and different driver/driven gas combinations with helium and carbon dioxide test gases using this model. Simulations were carried out using CFD solver FLUENT. Adaptive Mesh Refinement (AMR) technique was applied to accurately capture and resolve shock and contact discontinuities. At lower pressure ratios the different gas model is able to produce 20.4% and at higher diaphragm pressure ratios up to 33% increase in shock Mach number when compared to the similar driver-driven gas model.