Investigations of the Effect of Constant-Area Section on Thermal Choking in a Dual-Mode Scramjet Combustor

Abstract

The present study attempts to fix the location of thermal throat by employing transverse fuel injection downstream and adding a short constant-area section in the divergent part in a realistic scramjet combustor configuration in order to depress the pressure rise effects on the isolator. Ground tests using a direct-connect model along with pressure measurements and three-dimensional numerical simulation are also performed for the present investigations. The results indicate that the thermal throat is fixed in the constant-area section for the configuration with a short constant-area section in the divergent part. Numerical simulations also indicate that the constant-area section is helpful for ignition and flame holding. The configuration with a short constant-area section increase heat release in the combustor and decrease entropy production. Numerical simulation results imply that there could exist more than one thermal throat in dual-mode scramjet combustor, and the constant-area section in a divergent part could reduce the number of thermal throat.