The paper considers verification method for numerical modelling of bodies in viscous flow. The verification is based on approximate semi-empirical approach. The approach uses experimental data for flat plate and "effective length" method. One can apply approximate approach to estimate friction coefficient and specific thicknesses of boundary layer for axisymmetric objects placed in viscous flow. The approach is generalized for the flows with small angles of attack without separation effect. Practical aspects of approximate approach are described. Described approach can be used for verification and improving of numerical models in the case of lack of experimental data.