Papers by Keyword: Forward-Facing Cavity

Abstract: This paper focus on the detailed influence of forward-facing cavity on the opposing jet. The flow field of a hemisphere nose-tip with the combined configuration was simulated numerically and the surface heat flux distribution was obtained. The numerical results show that a suitable cavity is helpful for the opposing jet. With the same total pressure, the single opposing jet even can’t form a stable flow field and there is no cooling effect.

Abstract: In this paper, the unsteady flow field formed by the hemisphere nose-tip with forward-facing cavity and opposing jet combined thermal protection system (TPS) under high speed free stream flow (Ma4.98) was investigated numerically. The periodic variation of the drag coefficient and the flow field of the nose-tip were obtained. The numerical results show that a suitable cooperation between the opposing jet stream condition and the physical dimension of the cavity is necessary.

Abstract: In this paper, a thermal protection system (TPS) of opposing jet combined with a forward-facing cavity in hypersonic flow was investigated numerically. The flow field parameters and heat flux distribution along the outer body surface are obtained. The thermal protection efficiency of the combined TPS and the single opposing jet TPS was compared. The numerical results shows that this combined TPS has a good effect on cooling the nose of hypersonic vehicle. The recirculation region plays an pivotal role for the reduction of heat flux. The exist of the cavity strengthen the cooling efficiency.

Abstract: Forward-facing cavity mounted on the blunt nose of hypersonic vehicle is a good choice to reduce the stagnation heating. Presently, the study on hypersonic vehicles nose tip with forward-facing cavity mainly focus on its thermology characteristic, and little work can be found investigating the effect of cavity on aerodynamic force for a holistic vehicle. The CFD method is developed to investigate the effect of cavity geometry on aerodynamic performance of hypersonic vehicle with a forward-facing cavity on the nose-tip. Drag coefficient, lift coefficient and pitching moment coefficient of the vehicle for different attack angle are calculated. It is found that the cavity length to diameter (L/D) can not be a characteristic parameter in aerodynamic research, though it was used as a main characteristic parameter in investigation on the thermal protection. The length of the cavity L has little effect on aerodynamic characteristic of the vehicle, and the cavity diameter D has a crucial influence on the aerodynamic performance and the aerodynamic performance decrease with the D increasing. With the attack angle increasing, the drag coefficient, lift coefficient, pitching moment coefficient and lift-drag ratio of the hypersonic vehicle all increase.