The surface renewal approach to turbulence: A consideration of the assumption of segregation and the simplified treatment of the interfacial conditions

Abstract Implicit in surface renewal based formulations for turbulent convective transport is the assumption that each element of fluid that participates in the surface renewal process is segregated from the surrounding fluid. In addition, these analyses have almost exclusively employed simpe interfacial conditions. Consideration is given in this study to implications pertaining to the predictive capabilities of the surface renewal approach which are related to these factors. The results of this study both reinforce the acceptability of the simplified treatment of the interfacial conditions, and indicate that the assumption of segregation does not adversely affect the predictions for the mean transport properties other than r.m.s. fluctuations. It is concluded that the assumption of segregation does affect r.m.s. wall temperature fluctuations.