Aerodynamic Investigation of Shrouded Rotors with Dual Exit Channels

Abstract

The growing need for rotary-wing aerial vehicles with high-speed forward movement and dependable hover performance is critical in various applications. Shrouded rotors enhance aerodynamic performance, create more overall thrust with the same power consumption as open rotors, and have a more uniform induced velocity flow field. This paper presents a parametric computational investigation centered on the hypothesis, that dividing the shroud exit channel into convergent inner and divergent outer channels would enhance flow uniformity, reducing power losses, and preventing airflow separation from the main shroud’s inner walls. The validity of this hypothesized concept is demonstrated through extensive Computational Fluid Dynamic (CFD) simulations. The paper includes a case analysis utilizing experimental data from a highly- maneuverable drone, named Navig8, equipped with a 9-inch shrouded propeller where various shrouded configurations are examined using Computational Fluid Dynamics. Results typically show an increase in total thrust with the incorporation of an inner shroud for a given power.