Aftbody Shoulder Effects on Laminar Lip Shock Free Interactions

Compressible Navier–Stokes simulations have been performed to study the laminar near-wake of two-dimensional adiabatic hypersonic blunt bodies. In particular, the modified free-interaction theory from previous work has been examined for cylindrical geometries with a truncated aftbody of finite shoulder radius. The geometries investigated were a single-parameter family of geometries based on the ratio between the shoulder radius and the forebody radius. A series of simulations were performed over a range of Mach [Formula: see text] and Reynolds number [Formula: see text]. The pressure rise due to the lip shock formation process was correlated to the properties of the boundary layer upstream of the shock wave boundary layer interaction. The interaction parameter [Formula: see text], is shown to be a function of a Reynolds number calculated with post-shock properties, and the shoulder radius as the relevant length scale (the shoulder Reynolds number). It has been shown that for a shoulder Reynolds number less than approximately 1500, this interaction is highly Reynolds number dependent. Additionally, it has been shown that for a shoulder Reynolds number less than approximately 330, the separation point exists past the shoulder on the base. This work effectively connects the theory of separation, wake, and lip shock formation between bodies of curvature and finite bases.