Numerical simulations of a rotor in confined areas including the presence of wind

Abstract

This work explores the high fidelity numerical aerodynamic computations of a helicopter rotor placed in various confined areas including the presence of wind. Two numerical methods, fully blade resolved CFD and the actuator line method (ALM), are compared against each other and experimental data in terms of global rotor loads including thrust, torque, pitching and rolling moments. A detailed assessment of the two methods outside-of-ground effect (OGE) is performed covering blade loading, rotor inflow, wake geometry and fuselage surface pressure coefficient. Excellent agreement and consistency are found between the two numerical methods. Both are able to accurately predict the trends of the experimental rotor in most cases. However, some conditions remain challenging from either a modelling or computational standpoint. The overall agreement of the two numerical methods with the experimental data demonstrates their capabilities in accurately predicting rotor flows in challenging confined areas and the appropriateness of the ALM to replace more costly fully blade resolved simulations.