Abstract:

ESDU 87012 provides an introduction to buffeting, its sources, prediction and control. Types of flow separation occurring on aerofoils and wings are discussed and their effect on pressure distribution and steady and unsteady measurements considered. These effects are used to indicate the influence of Mach number and incidence on the growth of separated flow and buffet. Methods for assessing buffet onset are considered, and the use of wind-tunnel tests to predict onset on wings is explained. Wind-tunnel buffeting tests on a systematic series of wings are reviewed to show the effect of such design variables as sweep, camber, thickness/chord ratio, position of maximum thickness and aspect ratio. Brief notes are included on the alleviation and control of buffeting, and two special cases of buffet that are susceptible to theoretical treatment, pressure fluctuations in two-dimensional separation bubbles and shock oscillations at transonic speeds, are discussed.