Heat flux distribution and deviation of stagnation point on blunt body under atmospheric dense environment

Rocket sled is a large ground dynamic test system that obtains model test data on a special ground track. To accurately predict heat flux on rocket sled's surface, a similar blunt body model is utilized in this study. The effects of flow temperature, Mach number, wall temperature, angle of attack and other parameters on aerodynamic heating at standard atmosphere are analyzed based on computational fluid dynamics (CFD) simulation. The results show that heat flux at stagnation point is 4 MW/m2 at Mach 5. However, maximum heat flux on surface of blunt body head is 13 MW/m2, which deviates 5 mm from stagnation point in horizontal direction. These deviation points are distributed around axis of the cone, forming a band called pseudo-stagnation ring. In two dimensions, bluntness and flight height of cone directly affect position of “pseudo-stagnation point”. This position gradually approaches stagnation point as flight altitude increases. At 30 km altitude, “pseudo-stagnation point” position will not be offset. And at an altitude of 20–30 km, “pseudo-stagnation point” quickly falls back to the stagnation point. Additionally, pseudo-stagnation point's displacement is inversely related to cone's bluntness, and an increase in angle of attack augments separation from stagnation point on both windward and leeward surfaces.