DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Reduction of V/STOL Downwash Effects by Jet Exhuast Flow Control.
Final rept. Jul 73-Jun 74,
CIVIL ENGINEERING LAB (NAVY) PORT HUENEME CALIF
Pagination or Media Count:
The performance of VSTOL 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 Froesslings solution for boundary layer thickness and Glauerts solution for wall jet thickness. Author
APPROVED FOR PUBLIC RELEASE