BOUNDARY-LAYERS ON CHARACTERISTIC SURFACES FOR TIME-DEPENDENT ROTATING-FLOWS

Time-dependent motion of a fluid in a container rotating at Ω is characterized by boundary layers on the container surfaces if ν/Ω, where v denotes kinematic viscosity, is small compared to the square of a typical length of the container. Let the frequency of the motion, measured in a corotating coordinate system, be ΩΩ. If Ω1, then the length scale of the boundary layer is (ν/Ω)1/2, unless Ω is equal to twice the normal component of the unit rotation vector. If Ω does equal twice the normal component of the unit rotation vector, scales of (ν/ΩL2)1/3L and (ν/ΩL2)1/4 L are possible. If the normal vector and rotation vectors are parallel, the former scale vanishes. © 1983 by ASME.