The paper presents a computational study of the transonic shock-buffet flow instability phenomenon on three- dimensional wings. Reynolds-averaged Navier Stokes simulations were conducted on three wing configurations, all basedontheRA16SC1 airfoil, at shock-buffet flow conditions.Numerical validation is presented for theOAT15Aand RA16SC1 swept wings based on wind-tunnel experiments. The simulated configurations include infinite-straight, infinite-swept, andfinite-swept three-dimensional wing models of several sweep angles andspan lengths. Basedon the results, the effects of three-dimensional flow, wing sweep, and span length on the shock-buffet characteristics are identified. For small wing-sweep angles, the fundamental shock-buffet instability mechanism remains similar to the two-dimensional mechanism, which is characterized mainly by chordwise shock oscillations. For moderate sweep angles, a phenomenon of lateral pressure disturbance propagation is observed. This phenomenon is essentially different from the two-dimensional shock-buffet mechanism yet results in oscillations of the sectional aerodynamic coefficients. The paper presents and discusses both phenomena, and it suggests a connection between them. For high- wing-sweepangles, thewingis stalledandshock buffet is eliminated.Forlow-aspect-ratio wings, the flow is dominated bytip vortices,andshock buffet is eliminated. Forhigh-aspect-ratio wings, wingtip effects are minorandlimited to the tip region. For intermediate-aspect-ratio cases, tip vortices and shock-buffet interaction results in irregular shock oscillations.
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