A Study of using Wall Function for Numerical Analysis of High Reynolds Number Turbulent Flow

In this paper, a numerical study is carried out for super-pipe, flat plate and axisymmetric body flows to investigate a validity of using wall function and high y 1 + in calculation of high Reynolds number flow. The velocity profiles in boundary layer agree well with the law of the wall. And it is found that the range of y + which validated the logarithmic law of the wall grows with increasing Reynolds number. From the result, an equation is suggested that can be used to estimate a maximum y 1 + value of validity of the log law. And the slope(1/K) of the log region of the numerical result is larger than that of experimental data. On the other hand, as y 1 + is increasing, both the friction and the pressure resistances tend to increase finely. When using y 1 + value beyond the range of log law, the surface shear stress shows a significant error and the pressure resistance increases rapidly. However, when using y 1 + value in the range, the computational result is reasonable. From this study, the use of the wall function with high value of y 1 + can be justified for a full scale Reynolds number ship flow.