Reduced-Order Inflow Model for Propeller-Airframe Flow Interaction Noise Assessment

In Phase I, our research team will focus on the fundamental interaction of the wake from a horizontal flat plate with a pusher-prop, using experimental and numerical techniques.The experimental campaign will include acoustic measurements at various locations along the airframe-propeller setup, characterizing the velocity distribution upstream and downstream of the propeller disk using stereoscopic particle image velocimetry (PIV), and measuring the propeller blade loads.The experiments will be performed inside an open-jet wind-tunnel and fully anechoic chamber, and the measurement data will provide the framework for developing a reduced-order representation of the unsteady inflow to the propeller. This reduced-order model will be used to obtain estimates of the interaction acoustics in our numerical framework. The efforts dedicated in Phase I towards the development and validation of this framework for noise assessment for the fundamental configuration will provide the ideal launch-pad for testing, substantiating and refining the model further in Phase II and beyond. These numerical modeling efforts in Phase II will be complemented by experimental measurements on more representative propeller-airframe designs and configurations. Development of strategies for scaling the reduced-order model to be more representative of full-size systems will be initiated in the Phase I program.