ABSTRAKT

The paper presents an analysis and generalization of experimental data on the unsteady heat transfer of gases and liquids flowing in the tubes under the conditions of heating, cooling and variation in the flow rate, heat release in the tube walls, and entrance flow temperature. The experimental investigations were provided in round tubes in wide range of regime parameters. Comparison of the analytical and experimental data has made it possible to find a tube radius distribution of turbulent flow parameters, and to specify the effect of an unsteady impact on turbulent flow characteristics with the experimental ones. As a result, the generalizations have been derived to calculate unsteady heat transfer coefficient. Engineering methods are proposed to predict real unsteady thermal processes.