A new method for heat reduction design using the offset phenomenon of the peak heat flux and recombination structure of the blunt body on the ground

Abstract

The rocket sled is an experimental ground-based device for hypersonic vehicles, which uses rocket boosters with strong thrust to obtain the aerodynamic characteristics of the load. In order to accurately predict the heat flux of the rocket sled at Mach 8–10, a geometrically similar blunt body configuration was analyzed in this study. Computational fluid dynamics (CFD) simulations were utilized to investigate aerodynamic heating under ground-level conditions. Using the Gupta chemical reaction model, the effects of incoming temperature, Mach number, bluntness, and wall temperature on aerodynamic heating at standard atmosphere are analyzed. The results showed that the maximum surface heat flux of the blunt body is not at the stagnation point, and deviates from it under the ground environment. The position of the maximum heat flux is only dependent on the bluntness and not on other parameters. And based on this peculiar phenomenon, using two kinds of blunt bodies (the radius of a blunt body is r_b, and the other is r_n) forms a new structure to reduce heat at the ground. And the intersection point (Po_ins) can be at three different locations. The Po_ins were taken downstream of the heat flux offset point (X_ins=0.005 m), heat flux offset point (X_ins = 0.02 m), and upstream of the heat flux offset point (X_ins=0.08 m). When the r_b/ r_n is 2 and the X_ins is 0.005 m, the peak of heat flux is 99.6 MW/m², which is 18.1 % lower than the highest heat flux of the single blunt body of a radius of r_b. For X_ins = 0.05 m and 0.08 m, the peak of heat flux is close to the heat flux of the peak offset point of the single blunt body with a radius of r_b.