Describe in physical terms the matching conditions that must

Describe in physical terms the matching conditions that must be applied to resolve coupling between the tube wall movement and the flow field within the tube

Solution

>> To resolve coupling between the tube wall movement and the flow field within the tube, the most significant factor is SHEAR STRESS between them.

>> Physically, this shear stress is the force per unit area that must be applied to the upper plate at all times so that the velocity of the plate can be maintained constant in the presence of the friction in the fluid.