Turbulent Rayleigh-Taylor instability experiments with variable acceleration

Turbulent mixing due to the Rayleigh-Taylor instability is experimentally found to vary strongly with the temporal acceleration profile g (t). For constant g, the bubble amplitude h₁ increases as gt^2 consistent with previous results. For sustained acceleration profiles with dg/dt0, h₁ increases, not with the displacement Z= dt'dt, but with the length S=0. 5 dt^2. For an impulsive acceleration, mixing is minimized with h₁Z^0. 4. These results are used to test mix models. 1996 The American Physical Society.