THE DUCTED PROPELLER IN STATIC AND LOWSPEED FLIGHT
Abstract
A theory is developed for the steady aerodynamic loading on a ducted propeller with finite blade number in static and low-speed flight. The interaction of the higher harmonics with the steady loading is clarified and it is shown that, in a rigorous sense, a high blade-number restriction is required. For a shroud of small camber and zero thickness an analytic solution is obtained, together with simple expressions for shroud thrust and surface pressures, subject to a constant-pitch assumption on the trailing propeller vortices. To be more precise, the pitch hypothesis is dropped and an alternative iterative solution pursued. The final results, however, of an illustrative calculation indicate that the two solutions do not differ significantly. Results of a limited comparison with experiment are quite reasonable.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0608526
Entities
People
- D. E. Ordway
- M. D. Greenberg