Reduction of V/STOL Downwash Effects by Jet Exhuast Flow Control.
Abstract
The performance of V/STOL aircraft is influenced significantly by ground effects during landing and takeoff when the propulsive flow of the aircraft is directly dowward. To mitigate downwash effects, a new landing mat concept was developed at Civil Engineering Laboratory whereby exhaust flow is controlled by either a very thin array of diamond patterns or parallel ribs. The impinging jet flow aligns itself with the long axis of the grid pattern, expanding in two directions along a single line rather than radially outward over the plane of the ground. Grid height or thickness is small compared with jet diameter. A method for calculating grid height was developed by combining Froessling's solution for boundary layer thickness and Glauert's solution for wall jet thickness. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1975
- Accession Number
- ADA021965
Entities
People
- Dana Williams
Organizations
- Naval Facilities Engineering Service Center