downwash

downwash

[′dau̇n‚wäsh]

(fluid mechanics)

The downward deflection of air, relative to the direction of motion of an airfoil.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

downwash

i. Fluid flow moving at a deflected angle after deflection by helicopter rotors and measured parallel to the disc.
ii. Fluid flow deflected at an angle more perpendicular to the motion of the airfoil, measured in the plane parallel to the plane of symmetry close behind the trailing edge.
iii. Air that has passed around the main wing or rotor and now strikes the tailplane at an angle different from the direction of flight.
iv. Air that has been accelerated downward by the action of the rotors of a helicopter.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved