High Efficiency Hypersonic Control Flap (HEHCF) for High-G Manuevering

Hypersonic vehicles operate at high-temperature, in a highly viscous flow field, for extended duration. Shock waves and boundary layers interact (SBLI) at the control surfaces of these vehicles and further increase viscous drag and aerothermal heating compared with the base vehicle. The SBLI also dramatically raises the achievable pressure ratio at the control surface if well controlled. Over long distances, small drag losses and aerodynamic inefficiencies have a large cumulative effect that manifest themselves as a decrease in range, lift-to-drag ratio, and overall high-speed performance / maneuverability. A novel, multi-element control surface is proposed to increase maneuverability and efficiency across the full operating range of Mach numbers and altitudes flown by hypersonic glide bodies that exploits the pressure increase due to SBLI. The increase in control surface pressure ratio will generate a direct increase in vehicle maneuverability while also minimizing drag at low angles of attack. Experimental test campaigns in two wind tunnels at Mach 6, 8, and 14 will characterize the new design and make direct comparisons with a conventional single-element system. Measured quantities include lift, drag, pressure, heat flux, and dynamic pressure. High-enthalpy experiments will also be conducted in an arc-jet to examine high temperatures, real gas effects. Approved for Public Release | 20-MDA-10398 (2 Mar 20)