Numerical Analysis of a Cycloidal Rotor under Diverse Operating Conditions and Altitudes

The current paper presents the numerical study of the downwash flowfield characteristics in a cycloidal rotor at close-ground altitudes. In an aircraft equipped with this kind of thruster, the downwash flow plays significant role in different flight modes. The interaction of this downwash jet with ground in effective altitudes is studied using CFD simulations in OpenFOAM. Several operating conditions such as pitching oscillation angles, rotation speeds and height levels are all considered in this work. The results declare that close-ground operating states affects the performance of cyclorotors. The vertical and horizontal forces of a single blade is also analyzed in a complete cycloid in different operating conditions. A lead and lag in maximum and minimum extremes of force curves of a single blade is obtained while being subjected to different functional conditions. The presented results highly support an active control methodology to be taken for both pitching oscillations and rotation speeds as essential strategy for operating at optimum state.