Sahel D., Ameur H., Benzeguir R., Kamla Y. «Prediction of heat transfer development in a smooth tube» Инженерно-физический журнал, 91, № 3, с. 728-733 (2018)

The heat transfer characteristics in a smooth tube are studied. Based on the available experimental data, a new correlation is proposed to predict the heat transfer coefficients inside tubes of different lengths. The predicted results show that for a range of L/D from 26.31 to 58.14, the heat transfer coefficient may be reduced by 20.56% and increased by 13.31% at the beginning and at the end of this range, respectively. The results obtained from the proposed correlation are compared with other analytical and experimental data, and satisfactory agreement is found.

Salomatov V.V., Puzyrev E.M., Salomatov A.V. «Microwave heating of a liquid stably flowing in a circular channel under the conditions of nonstationary radiative-convective heat transfer» Инженерно-физический журнал, 91, № 2, с. 411-427 (2018)

A class of nonlinear problems of nonstationary radiative-convective heat transfer under the microwave action with a small penetration depth is considered in a stabilized coolant flow in a circular channel. The solutions to these problems are obtained, using asymptotic procedures at the stages of nonstationary and stationary convective heat transfer on the heat-radiating channel surface. The nonstationary and stationary stages of the solution are matched, using the "longitudinal coordinate-time" characteristic. The approximate solutions constructed on such principles correlate reliably with the exact ones at the limiting values of the operation parameters, as well as with numerical and experimental data of other researchers. An important advantage of these solutions is that they allow the determination of the main regularities of the microwave and thermal radiation influence on convective heat transfer in a channel even before performing cumbersome calculations. It is shown that, irrespective of the heat exchange regime (nonstationary or stationary), the Nusselt number decreases and the rate of the surface temperature change increases with increase in the intensity of thermal action.

Salomatov V.V., Puzyrev E.M., Salomatov A.V. «Microwave heating of a liquid stably flowing in a circular channel under the conditions of nonstationary radiative-convective heat transfer» Инженерно-физический журнал, 91, № 2, с. 411-427 (2018)

A class of nonlinear problems of nonstationary radiative-convective heat transfer under the microwave action with a small penetration depth is considered in a stabilized coolant flow in a circular channel. The solutions to these problems are obtained, using asymptotic procedures at the stages of nonstationary and stationary convective heat transfer on the heat-radiating channel surface. The nonstationary and stationary stages of the solution are matched, using the "longitudinal coordinate-time" characteristic. The approximate solutions constructed on such principles correlate reliably with the exact ones at the limiting values of the operation parameters, as well as with numerical and experimental data of other researchers. An important advantage of these solutions is that they allow the determination of the main regularities of the microwave and thermal radiation influence on convective heat transfer in a channel even before performing cumbersome calculations. It is shown that, irrespective of the heat exchange regime (nonstationary or stationary), the Nusselt number decreases and the rate of the surface temperature change increases with increase in the intensity of thermal action.