Theoretical problems of calculation methods of turbulent flows

Abstract

Turbulent flows represent the non-stationary chaotic motion of liquid or gaseous media. Thus, it is impossible to give a strict mathematical description of the real picture of the turbulent flows. As a result, the virtual flow of the so-called quasi-stationary flow is realized. The transition to this process is carried out either by statistical methods of averaging non-stationary flows, or by the simplest temporal averaging proposed by O. Reynolds. These materials show the difficulties encountered within the process of averaging of Naiver-Stokes equations of motion, and indicate that it is more expedient and physically reasonable to average the equations of motion of liquid and gaseous media in voltages. To simplify the averaged equations of motion, we make a comparison among the values of turbulent stress gradients. And, basing on the proposed mechanism for the development of turbulence, we show that from a physics aspect, L. Prandtl’s semi-empirical theory of turbulence is most physically reasonable.Turbulent flows represent the non-stationary chaotic motion of liquid or gaseous media. Thus, it is impossible to give a strict mathematical description of the real picture of the turbulent flows. As a result, the virtual flow of the so-called quasi-stationary flow is realized. The transition to this process is carried out either by statistical methods of averaging non-stationary flows, or by the simplest temporal averaging proposed by O. Reynolds. These materials show the difficulties encountered within the process of averaging of Naiver-Stokes equations of motion, and indicate that it is more expedient and physically reasonable to average the equations of motion of liquid and gaseous media in voltages. To simplify the averaged equations of motion, we make a comparison among the values of turbulent stress gradients. And, basing on the proposed mechanism for the development of turbulence, we show that from a physics aspect, L. Prandtl’s semi-empirical theory of turbulence is most physically reasonable.