Turbulent gas flow structure under unsteady hydrodynamic conditions

The data obtained on the structure of a turbulent circular tube gas flow in the case of hydrodynamic unstable influence of averaged velocity longitudinal and radial components fields, their pulsations and correlations. These are supplemented with the data on the influence of stationary conditions on the turbulent coefficient and heat transfer coefficient. The existence of the zone of greatest changes in the structure parameters is confirmed. It is found that the flow nonisothermicity enhances the influence of hydrodynamic instability. Under nonisothermal boundary conditions, after the removal of the effect, the return of structure characteristics to the stationary influence slow down considerably. A new dimensionless criterion of hydrodynamic instability is suggested.