Experimental investigation of a submerged subsonic inlet

The objective of this combined computational and experimental study is the design optimization of a generic flush mounted inlet, which minimizes flow distortion at the engine face. A series of experimental surveys were performed to validate the accompanying computations and to provide additional information regarding the Pareto Set of optimal designs. A stainless steel model with a removable submerged inlet (built using an FDM system) was fabricated and installed in the Rutgers University Low Speed Wind Tunnel. Detailed experiments were focused on the measurement of total pressure three diameters downstream of the exit of the inlet. A rotating multi-element pitot rack was fabricated and installed in the model, which was attached to the suction side of a blower to yield the appropriate mass flow rate through the inlet. Rutgers University thermal anemometry system was employed to verify velocity profiles obtained using pressure differential technique. A LabView program developed at Rutgers University controlled motion control, pressure, velocity and temperature data acquisition as well as management of the wind tunnel operations for all experiments. Experimental evaluation of the baseline inlet and optimum inlet for zero angle of attack and yaw showed consistent trend between experimental and computational results in reduction of the Distortion Coefficient (DC). Also, the Distortion Coefficient improved for the optimum inlet compared to the baseline inlet for negative angles of attack and all yaw angles.