Abstract
Taking into consideration the slippage in the boundary between a solid surface and a fluid flowing over it, the flow through an annulus is analysed.
A measurement method of the slippage is proposed by the authors. The thrust acting on the movable core supported on the adjacent fixed cores in the annulus, is measured to obtain the slippage independently of the viscosity coefficient of the fluid. In the investigation of the flow in the annuli whose walls had been treated with slippery material, the measurement method provided a conclusive check to measure the slippage.
