SIMILARITY LAWS FOR CONSTANT-PRESSURE AND PRESSURE-GRADIENT TURBULENT WALL FLOWS

It is well known that the nonlinearity of fluid mechanics equations makes all the dynamic equations of turbulent flows nonclosed. If one adds the equations for the new unknowns (higher-order moments), then the number of the unknowns in the equations will increase faster than the number of the equations themselves. Therefore the equations of turbulent flows cannot be solved without the use of some supplementary speculative closure hypotheses. Similarity and dimensional arguments are, apparently, the most important general methods for obtaining meaningful results without solving the dynamical equations (Bridgman 1932, Sedov 1959). This review is devoted to the similarity and dimensional analysis of some types of turbulent wall flows and compares the results obtained with experimental data.