Parametric geometry models for hypersonic aircraft: integrated external inlet compression

In this paper we are investigating a method for the design and integration of 3D external compression inlet geometries on parametric geometries of air-breathing hypersonic aircraft. We view the geometries as the first stage of a mixed compression inlet. The investigations are based on waverider geometries generated with the osculating cones waverider forebody design method. The osculating cones method is further utilized to create a second compression surface before the inlet cowl, essentially creating a second waverider geometry on the underside of the forebody. This way, we achieve greater compression for the part of the flow to be captured by the inlet cowl using a geometry that does not require sidewalls (like 2D ramps do), and has a potentially larger capture area than axisymmetric inlet geometries such as half-cones. The integration method is explained in detail, validated and further examined with CFD simulations. Those include measurements of the sensitivity of the flowfield to angle of attack, sideslip and Mach number changes. A number of options for designing the downstream internal compression part of the inlet are also discussed.