Flight Testing of a New Design Concept for Axisymmetric Inlets

This proposal identifies a flight test program on the F-15B at NASA Dryden to obtain off-design performance of high-speed inlets that incorporate a unique variable geometry system. The proposed effort accomplishes two objectives; validation of engine face distortion prediction by complex CFD codes and validation of a unique new approach to variable geometry for high-speed inlets. For supersonic cruise, this variable geometry concept allows the consideration of very high performance axisymmetric inlet designs that normally have required complex, heavy variable geometry concepts to effect the necessary throat area variation. The proposed concept also provides increased design options for hypersonic inlets. Aerodynamic design, model fabrication and flight testing of two inlets, one with the unique variable geometry and a baseline configuration, will be completed. This proposal responds to the SBIR subtopic by proposing a study in which prediction of inlet distortion by using complex CFD codes can be validated by comparison with data from a flight program. It is expected that this effort will also verify acceptable lower speed performance for an inlet designed to utilize the concept of this proposal. This advance in inlet technology will enable development of efficient and safe propulsion systems for supersonic or hypersonic vehicles.