An experimental and computational study showed that a passive boundary layer control device in the form of a step incorporated just downstream of a nozzle throat can be used to provide good thrust recovery. The nozzle without the step produced an overexpansion of the supersonic °ow. The computational study was performed for a full-scale nozzle under actual engine exhaust and ambient atmospheric...

In this paper, a new approach has been proposed to identify and model the dynamics of a highly maneuverable aircraft through fuzzy logic algorithm. In general, aircraft flight dynamics is considered as a nonlinear and coupled system whose modeling through fuzzy logic algorithm can be done using a few experimental flight tests data. In this study, for identification and modeling of the aircraft ...

A static model based on eye-heart vertical distance has been developed which predicts group mean G tolerances relative to the application of any of the following anti-G methods and/or physiologic responses: a) anti-G suit, b) reclined seat, c) anti-G straining maneuver (AGSM), d) positive pressure breathing (PPB), e) gradual onset of G, f) isometric muscular contraction, and g) leg elevation. T...

This paper documents recent advances towards an efficient computational method for accurately determining the static and dynamic stability and control (S&C) characteristics of high-performance aircraft and demonstrates how it may fit into the SEEK EAGLE Store Certification Process;. In contrast to the “brute force” approach to filling an entire S&C database for an aircraft, the present approach...

When a tactical aircraft sets out on a mission in dense airborne and surface RF (radio frequency) emitter environment, the pilot desires to minimize the use of the onboard fire control radar to remain “silent.” Consequently, the pilot heavily relies on the onboard passive sensors and offboard reports received from wingmen and other sources. The onboard sensors may include a RWR (radar warning r...

An understanding of the vortical structures which comprise the vortical flowfield around slender bodies is essential for the development of highly maneuverable and high angle of attack flight. This is primarily due to the physical limits these phenomena impose on aircraft and missile s at extreme flight conditions. Demands for more maneuverable air vehicles have pushed the limits of current CFD...

The free-to-roll technique is used as a tool for predicting areas of uncommanded lateral motions. Recently, the NASA/Navy/Air Force Abrupt Wing Stall Program extended the use of this technique to the transonic speed regime. Using this technique, this paper evaluates various wing configurations on the pre-production F/A-18E aircraft and the Joint Strike Fighter (F-35) aircraft. The configuration...