Dynamic-pressure measurement, in ground effect, have been obtained about a single-rotor helicopter and a dual-propeller VTOL (Vertical Take-Off and Landing) aircraft. The results indicate that the slipstream dynamic pressure along the ground, some distance from the center of rotation, is not a function of disk loading but merely a function of the gross weight or thrust of the aircraft. Furthermore, for a given gross weight the thickness of this outward flowing sheet of air is less for a small-diameter propeller (higher disk loading propeller). The variation of the dynamic-pressure flow field for single and dual propellers or rotors is significantly different in the plane of symmetry between the two rotors than in a direction normal to this plane. The interaction of the two flows produces a region of upflow in this plane where the fuselage is located, and the decay of the maximum dynamic pressure with distance ahead of the fuselage is slower.
An Investigation of the Effect of Downwash from a VTOL Aircraft and a Helicopter in the Ground Environment
1961-10-01
Miscellaneous
No indication
English
Investigation of effect of downwash from VTOL aircraft and helicopter in ground environment
Engineering Index Backfile | 1961
|Downwash Impingement Design Criteria for VTOL Aircraft
NTIS | 1964
|