Unsteady Wall Shear Stress Model for Pressure Transient Problems in Laminar and Turbulent Pipe Flows

Abstract

A transient shear stress model for the solution of water-hammer problems for laminar and turbulent flows in pipes is presented. The model is based on an expansion of the radial
profile of the axial velocity in exponential and polynomial functions, and the solution of the resulting set of equations by the method of characteristics. The present model can be
included with only minor modifications into any existing code based on the characteristics method.
The new model is tested against both experimental results and mathematical models and numerical simulations of other anthors, showing good agreement.