A new algebraic relation for calculating the Reynolds stresses

An approximate Reynolds stress transport equation from a previously reported (Launder et al., 1975) model is simplified to obtain an algebraic expression relating these stresses to the mean velocity gradients in turbulent flows. The stress relation is restricted to fully turbulent high Reynolds number flows excluding the viscous sublayer. The suggested expression provides a better representation of the Reynolds stresses than does the eddy viscosity formula, and forms a relatively simple model for complex flows in combination with transport equations for the length scale of turbulence and the kinetic energy of turbulence.