The numerical simulation of a rotating propeller geometry entails a high computational cost. This is for two reasons: the mesh density increases considerably, over and above that of the airframe, when modelling propeller blades and the numerical simulation of rotating blades requires an unsteady calculation.

Nevertheless, not all studies require the same level of fidelity. The ARA Computational Aerodynamics Applied team offers a range of possibilities to model propellers according to the customer or application needs: from low-fidelity codes to different high-fidelity CFD advanced techniques used in the aerospace industry.

Strip Analysis	Actuator disk	Full modelling
In many studies, the flow around the blades is not of primary interest and the slipstream can be considered as stationary. When this approximation can be made, the full propeller can be replaced by a stationary propeller model which is less computationally expensive. The Solar–TAU RANS toolset used at ARA has got implemented an actuator disk model that consists of a simple geometry (disk) which applies stationary forces to the fluid equivalent to the ones that a full propeller would apply.  The formulation of the model allows the propeller thrust and power to be influenced by free-stream incidence and installation effects.