Optimization of a counter-rotating propeller in UAV application

The application of counter-rotating propellers has been adopted in UAV design in recent years. The presence of counter-rotating propeller improves total thrust and cancels out the torque. The aim of this paper is to employ a sensitivity study for the total thrust of a counterrotating propeller for UAV applications using computational fluid dynamics in hover condition. Two factors were investigated: propellers spacing and the difference between blades pitch angle. A counter-rotating propeller system was modeled in SolidWorks. The numerical investigations were carried out with ANSYS CFX. Shear Stress Transport (SST) turbulence model was used for steady state simulations with unstructured mesh. It was found that the total thrust of counter-rotating propeller is highly dependent on propeller spacing and the difference between blades pitch angle. An optimal design was found in terms of the total thrust.