Analysis of Off-Design Operation of a Supersonic Ramped 3-D Inlet

The following document will outline an evaluation of a supersonic ramped 3-D planar inlet with attached constant area isolator operated at off-design conditions. Particularly, the inlet is being investigated to evaluate the feasibility of increasing the operable Mach number range for a given inlet design. The inlet used in this test campaign has a design Mach number of 2.5 and is tested at the above design condition of Mach 4.0. The behavior of the inlet and isolator at this condition is evaluated by the shock structure present in the isolator section. The inlet start condition will be defined by the presence of a shock train in the isolator section. Schlieren imaging and pressure sensitive paint (PSP) techniques are employed in order to assess the presence of these shock structures in the inlet and isolator sections. To further assess the shock behavior at above-design conditions, the isolator section was back pressured. Lastly, a computational study was completed on a model of the inlet and isolator. For each of these methods, it was found that a stable shock train is present within the isolator section when the inlet and isolator are operated at the above-design Mach number of 4.0.