A state-space free-vortex hybrid wake model for helicopter rotors

This paper presents the development of a new hybrid wake model merging two distinctly different modeling approaches into a single, more comprehensive solution - specifically the finite state wake and the free-vortex wake. The objective of this work was to leverage the strengths of each, individually, creating a more flexible and extensible wake solution that could be used across the entire flight envelope of a helicopter. The results not only show that the two wake models can be successfully merged but they also complement each other demonstrating a synergy between the two solution methodologies. The results also demonstrate that a hybrid wake is the mechanism by which the finite-state wake can impart a level of stability on the free wake allowing the free wake to generate consistent, repeatable results from hover through high speed forward flight.