Thrust Reversers - Aerodynamic Research

From: (R. & L. Chilukuri)
Organization: Univ of California at San Diego
Date:         14 Mar 95 02:34:34 
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One of the many Aero problems associated with the use of thrust reversers 
(T/R) is associated with the plume trajectory. 

Integration of a T/R with an aircraft is a painful process, especially 
for fuselage-mounted engines. During landing, the T/R plume washes over 
control surfaces and can cause severe rudder buffetting, pitch-up moment 
and tail rocking.

Many of the empirical models  that are available in the open literature, 
were developed using laboratory measurements of plume trajectory and 
spreading. These lab experiments were almost always performed for a 
simple configuration of a jet issuing from a flat plate into a 
cross-stream, with a flat (top hat) initial velocity distribution.

The flow within a thrust reverser geometry forces fluid to undergo nearly 
135 deg turn, before issuing out as a plume. Thus the starting velocity 
profile will be extremely skewed, and perhaps will contain 
counter-rotating vortices.

Does data exist on the effect of the initial velocity profile on plume 
trajectory and decay? How does one model (other than CFD) these flow 

					Thanks a bunch--
					Krish Chilukuri
					Aero Group Leader
					Rohr Inc.