Clarification of the Evaluation of Friction Work Transfer in Control Volume Analyses

Abstract

Friction work transfer in control volume analyses has been critically examined with special reference to the case when the friction force is not uniform over the boundary of the control volume. By considering a particular application of a Couette flow between a stationary smooth surface and a moving rough surface with a positive pressure gradient, it is shown that an inconsistency may be introduced in quantifying the work transfer rate when the modelling of the flow is on a one-dimensional basis.