Experimental Characterization of a Tangent Ogive Cylinder body with Fins, Longitudinal Protuberances and a Chin Inlet in the FSU Polysonic Wind Tunnel (038734)

The design of supersonic and hypersonic inlets that operate efficiently over the entire flight regime has been one of the primary challenges in the design of air-breathing engines. Chin inlets are relatively superior in performance over a wide range of flow and geometric parameters and offer better packaging capability in case of integrated propulsion engines. The incoming air at supersonic or hypersonic speed needs to be compressed and delivered to the combustor with minimal losses and efficient diffusion. In traditional inlets, the flow is decelerated through a series of oblique shock waves, which eventually terminate in a normal shock followed by a subsonic diffuser. The interaction of these shocks, especially the terminal normal shock, results in strong Shock Wave – Boundary Layer Interactions (SWBLI) inside the inlet. This leads to degradation in the inlet performance in terms of significant pressure losses; non-uniform flow, flow unsteadiness in the duct; local, or, in severe cases, global separation. These problems can dramatically compromise the system performance in terms of pressure recovery, thrust loss, inlet ‘buzz’ and in extreme cases inlet unstart. Therefore, it is very important to perform a detailed characterization of an inlet over a range of Mach and Reynolds numbers, angle of attack and yaw, and mass flow conditions to examine its performance. Our approach is twofold: 1) to build our understanding of the existing knowledge of aerodynamic characteristics of long slender bodies with fins and progressively add complexities in terms of longitudinal protuberances (wire tunnels) and air-breathing capabilities; 2) characterize isolated inlet and study its performance over a range of geometric and flow conditions.