Computational Aerodynamic Interaction of Hypersonic Flow with Pin-Protuberance on Blunted Cones

Computational study of the aerodynamic behavior of blunt nose bodies like conic geometries with lateral pin-protuberance in hypersonic flow was investigated. The pressure distribution along the cone's longitudinal axis in the presence of the cylindrical pin was studied using numerical simulations. Static aerodynamic coefficients in the Mach range of 5-9.7 at an angle of incidence of zero and negative 12A degrees were also computed. The numerical solution compared favorably with the experimental results that include the pressure distribution over the flat plate with square/cylinder pins, and with the experimental data of aerodynamic coefficients of generic cones. Further, validated numerical tool was used to investigate the flowfield interactions by correctly capturing dominant bow shock's location and its strength, regions of separated flow associated with the pin's upstream flowfield and the influence of low-pressure zone, in the aft of the pin. To study flight control of conic vehicles, it is important to estimate the effectiveness of a net increase in the normal aerodynamic force and pitching moment generated by the flow interference and consequential pressure redistribution on the cone's surface. It is shown that a short lateral pin-protuberance has adequate effectiveness to control a conic vehicle at Mach number 5; a further increase in Mach number though requires pin-height extension. In view of that, a suitable pin-height adjustment commensurate to pitch attitude trajectory corrections is a workable idea, and the concept has potential of effective pitch attitude control of the cone-shaped vehicles.