Blade-Wake Interactions and Rotary Boundary Layers
The flows studied here are provoked mainly by a rotating configuration having one or more thin blades, with or without an external stream normal to the axis of rotation. The applications range from helicopters and airborne seeds to food mixers and hover mowers. Computations and analysis are described for the three-dimensional rotary boundary layer, which generally is steady only in the absence of the stream. The computational method appears robust and flexible, yielding results for a variety of rotary blade arrangements. The analysis then deals with cases of large gaps, small gaps, many blade and the far outboard response controlling the global spread influence. Interesting new phenomena are found concerning multiple blade-wake interactions, inner-outer-flow interactions at tiny angles of incidence, viscous-inviscid interactions especially near corners or trailing edges and blade tips, and a doubly viscous structure induced by a dense blade-gap arrangement. Further developments and discussion are presented at the end.
Proceedings of the Royal Society of London Series A
- Pub Date:
- June 1996