Advances in cfd & actuator disk models for helicopter aerodynamics

This contribution describes a new computational model for the aerodynamic flows past a complete helicopter in- and out of ground effect. The model is based on an unsteady RANS code, coupled with an actuator disk and blade element method for the rotors. The implementation does not specifically require any changes in the computational mesh due to the presence of the rotor disk, an item of interest in other methods. The effect of the rotor is modelled iteratively as a momentum source distribution, which is the main novelty of this contribution. The disk loading is calculated with a convolution through a Gaussian function. Examples of results are shown for an airframe in low-speed forward flight in proximity to the ground (ground clearance h/d = 0.8).