Double boundary layers in oscillatory convective flow

Abstract

A study is made of the problem of the boundary layer on an infinite horizontal cylinder caused by oscillatory free convection when the temperature of the cylinder oscillates with frequency ω about a mean temperatureT∞, the temperature of the surrounding fluid. Special attention is given to the steady flow in the outer boundary layer and the appropriate Reynolds number. The governing equations are solved by the method of separation of the steady and the unsteady components of the flow field. It is shown that a large Reynolds number plays a significant role in the formation of the outer boundary layer in the oscillatory convective flows, while in the case of oscillatory flow in which the secondary flow is present due to the Reynolds stresses the large value of the parameterR/S is important.