On a time-dependent motion of a rotating fluid

摘要: We consider here the manner in which state of rigid rotation a contained viscous fluid is established. It found that motion consists three distinct phases, namely, development Ekman layer, inviscid spin-up, and decay residual oscillations. The layer plays significant role transient process by inducing small circulatory secondary flow. Low angular momentum entering from geostrophic interior replaced with greater convected inward to conserve mass. rotational velocity increases as consequence conservation momentum, vorticity increased through stretching vortex lines. spin-up time Boundary-layer theory used study phenomenon case general axially symmetric container configuration explicit formulas are deduced exhibit effect geometry spin-up. special cylindrical side walls also investigated this method. results very simple experiments confirm theoretical predictions.