The effects of gusts on the fluctuating airloads of airfoils in transonic flowUnsteady interactions of distributed and sharp-edged gusts with a stationary airfoil have been analyzed in two-dimensional transonic flow.A simple method of introducing such disturbances has been numerically implemented within the framework of unsteady, transonic small-disturbance theory. Representative solutions for various airfoils subjected to chordwise and transverse gusts show that the strength and unsteady motion of the shock wave on the airfoil significantly affect the flowfield development and, consequently, the dynamic airloads. Also a study was made of the reductions in the unsteady airloads that can be achieved by the proper active control motion of a trailing-edge flap, and a simple gust-alleviation strategy was developed. However, the chordwise pressure distributions associated with gusts are very different from those produced by trailing-edge flap oscillations. Consequently, the fluctuating lift and the unsteady pitching moments cannot both be eliminated simultaneously.
Document ID
19840056528
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Mccroskey, W. J. (NASA Ames Research Center Thermo- and Gas-Dynamics Div.; U.S. Army, Aeromechanics Laboratory, Moffett Field, CA, United States)