A Proposal for Modeling Intermittent Transitional Pulsatile Flows

The principal requirements in a turbulence model to be valid for the prediction of arterial flows are the ability to capture the consequences of laminar–turbulent transition that occur at various phases of the cardiac cycle and to yield accurate predictions of the wall shear stresses. These requirements are not immediately met by the majority of turbulence models since these have largely been formulated with reference to data from fully turbulent flows in approximate local equilibrium. The purpose of this paper is to report on recent progress in the development of a turbulence model that overcomes some of these limitations. The model is based on the solution of transport equations for two turbulence parameters that are zero–valued at a solid wall and an additional equation for intermittency. Comparisons with measurements obtained in oscillatory transitional flows in circular pipes show substantial improvements over existing closures.