Aerodynamic Heating In Missile-Fin Gap Region

Large heat transfer rates are a major source of possible failure in flight vehicles due to increases in temperature being linked to weakening material properties. Aircraft in high-Mach number flow generate excessive aerodynamic heat that may increase temperatures above limits of structural integrity. Even without reducing speed or changing material, it is possible to mitigate heat transfer by altering vehicle geometry. The purpose of this thesis is to study the extent of heat transfer in gap regions of various sizes by computationally simulating flow over an idealized missile-fin configuration. Maximum levels of heat transfer are analyzed as well as surface distributions that identify key design points. The Department of Defense software package with computational fluid dynamics capabilities, Kestrel, was employed to use the Reynolds-averaged Navier-Stokes equations to simulate turbulent Mach 6 flow over the missile model. Results are compared to data obtained by the Air Force Research Laboratory via wind tunnel tests of the same flow. Experiments and simulations both found an order of magnitude increase in heat transfer when an offset fin was attached, but this heating could be reduced by minimizing the offset distance. Simulated baseline properties agreed very well with experimental measurements and simulations of the gap region more precisely identified the locations of maximum heating.