Numerical simulation of aerodynamic interactions among helicopter rotor, fuselage, engine and body of revolution

Numerical simulations of helicopter aerodynamic interactions among the main rotor, fuselage, engine inlets/outlets and slung loads of specific geometries have been conducted by very few researchers. In this work, the steady-state compressible Reynolds-averaged navier-stokes equations are solved to study the aerodynamic interactions among helicopter rotor, fuselage, engine and body of revolution in three cases, namely MI-171V5, ROBIN and UH-60A. In the first case, the downwash flow provided by the rotor of the uniform actuator disc model induces a significant deflection of the airflow velocity. The vortex-shaped distribution and evolution are discussed in detail. The engine can effectively change the overall flow field. The asymmetry of the flow field is observed by using the non-uniform actuator disc model. Qualitative analysis of ROBIN and quantitative computation of UH-60A show a consistent accuracy of the rotating reference frame model for rotor. The blade tip vortex motion of UH-60A is simulated and its radial position prediction is compared to empirical formulas. While performing flow of UH-60A in hover, both the fuselage normal force and rotor lift decrease because of the impact of the body of revolution.