Flow field disturbance due to inflight NASA DC-8 inboard thrust reverser deployment

Abstract

An investigation of the wing upper surface flow field disturbance due to inflight inboard thrust reverser deployment on the NASA DC-8-72 is outlined and discussed in detail. The purpose of this flight test was to obtain tufted flow visualization data which demonstrates the effect of thrust reverser deployment on the wing upper surface flow field to determine if the disturbed flow regions could be modeled by computational methods. The investigation included symmetric thrust reversals of the two inboard engines to monitor tuft and flow cone patterns as well as the character of their movement at the nominal Mach numbers of 0.55, 0.70, and 0.85. The tufts and flow cones were photographed and videotaped to determine the type of flow field that occurs with and without the thrust reversers deployed. In addition, the normal NASA DC-8 onboard Data Acquisition Distribution System was used to synchronize the cameras. Three distinct flow patterns associated with the above Mach numbers were sketched from the motion videos and discussed in detail. Other relevant aircraft parameters, such as angular orientation, altitude, and Mach number, are also discussed. (Author)