Heat reduction using conterflowing jet for a nose cone with aerodisk in hypersonic flow

Numerical simulations of a 2D axisymmetric aerodisked nose cone in hypersonic flow are conducted, and innovative techniques involving forward injection of the gas from the stagnation point of the sphere are investigated; techniques include the injection of various counterflowing jets (helium or carbon dioxide) as a coolant jet from the nose cone behind the aerodisk. In this study, the characteristics of the various jet conditions of a counterflowing jet on a cone surface were investigated numerically to improve performance of the jet on heat reduction at the surface of a nose. The compressible, unsteady, axisymmetric Navier-Stokes equations are solved with SST turbulence model for free stream Mach number of 5.75 at 0 degrees angle of attack with and without gas injection. According to the investigation of various conditions of jets, important phenomena of flow field and some effective jet conditions are found. Heat transfer results show a significant reduction in heat flux, even giving negative heat flux for some low pressure ratio, indicating that the flow wetting the model had a cooling effect which could significantly impact thermal protection system design. The findings suggest that high-speed vehicle design and performance can benefit from the application of counterflowing jets as a cooling system. (C) 2014 Elsevier Masson SAS. All rights reserved.