  We simulate numerically convection in a rectangular cell filled with an ideal
gas rotating about an axis perpendicular to the direction of gravity. This
configuration corresponds to an experiment with a convection cell placed in a
rapidly rotating centrifuge in which the centrifugal force plays the role of
gravity. The compressibility of the gas in combination with the rotation of the
cell leads to a drifting mode at the onset of convection. The drift persists
despite the presence of sidewalls and is rapid enough to cause the anelastic
approximation to fail at parameters typical of realizable laboratory
experiments. The global spanwise rotation forces the flow to be 2D unless the
Rayleigh number is sufficiently large. The main properties of compressible
convection in 2D and 3D are compared.
