Modeling Propeller Flow-Fields Using CFD

Abstract

This paper documents work that was done in support of the NLOS-T (Non-Line-of-SightTransportation). The NLOS-T is a conceptual vehicle that will be canister-launched, deploy wings and control surfaces, and then fly to a destination within approximately 15 to 20 minutes of the launch point. An electric propeller with a diameter of approximately 20 inches provides the sustain propulsion after the initial launch. An obvious question is to what extent does the propeller flow-field affect the vehicle aerodynamics and stability? A more basic question is what does it take to adequately model a propeller flow-field with CFD? This paper will describe the approach taken to answer both of these questions. To answer the latter question, a basic investigation was conducted using a propeller-spinner geometry, without the rest of the airframe. The results of the basic investigation were then applied to a rotorcraft test case, where experimental data was available, as a validation of the lessons learned. Finally, simulations of the full aircraft were carried out to determine the propeller effects.