Evaluation of a Combined Momentum Theory and Simple Vortex Theory (CMTSVT) Inflow Model for UAM Applications

Abstract

This paper uses the combined momentum and simple vortex theory (CMTSVT) inflow model to study effects of rotor-on-rotor interference on induced power predictions for different multirotor configurations. It builds upon the previously completed validation with the Harrington coaxial rotor which showed that this simple analytical model could capture the overall rotor-on-rotor wake interference effects in the rapid estimation of rotor power without coupling it with a blade element rotor model. Since it has already been shown that the CMTSVT inflow model can serve as a viable tool in the early design stages of vehicle configuration and sizing trade studies, this paper focuses on applying this model to analyze the effect of rotor arrangement on individual rotor performance, using the plus and cross quad-rotor configurations. Power predictions based on self-induced and interference inflow are included, in addition to first harmonic inflow components to gain further insight. A comparison of the obtained results with existing literature on rotor arrangement sensitivity further validates the applicability of the CMTSVT inflow model in rapid estimation of rotor-on-rotor inflow interference and its effect on rotor power for its use in the early design phases of advanced multi-rotor vehicle configurations.