Review of Buoyancy-Induced Flow in Rotating Cavities

Buoyancy-induced flow occurs in the cavity between two corotating compressor disks when the temperature of the disks and shroud is higher than that of the air in the cavity. Coriolis forces in the rotating fluid create cyclonic and anticyclonic circulations inside the cavity, and-as such flows are three-dimensional and unsteady-the heat transfer from the solid surfaces to the air is difficult either to compute or to measure. As these flows also tend to be unstable, one flow structure can change quasi-randomly to another. This makes it hard for designers of aeroengines to calculate the transient temperature changes, thermal stresses, and radial growth of the disks during engine accelerations and decelerations. This paper reviews published research on buoyancy-induced flow in closed rotating cavities and in open cavities with either an axial throughflow or a radial inflow of air. In particular, it includes references to experimental data that could be used to validate CFD codes and numerical models.