How do you predict and mitigate transonic buffet on aircraft?

Transonic buffet results from shock wave oscillation and boundary layer separation interaction at high CL or Mach number. Prediction methods include: Unsteady RANS or DDES CFD capturing shock dynamics; wind tunnel testing with dynamic pressure measurements; and correlation methods based on pressure divergence boundaries. Mitigation strategies include: shock control bumps to weaken and stabilize shocks; vortex generators to energize the boundary layer; wing twist and camber optimization; and defining flight envelope limits (buffet boundary). The buffet onset boundary (1.3g buffet margin) is a critical certification requirement affecting maximum cruise altitude and maneuver capability.