Microwave Heating of a Liquid Stably Flowing in a Circular Channel Under the Conditions of Nonstationary Radiative-Convective Heat Transfer
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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.
Keywordsmicrowave radiation heat radiation nonstationary heat transfer stationary heat transfer round channel stabilized flow radiative-convective heat transfer Nusselt number Stark number
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- 1.E. C. Okress, Microwave Power Engineering, Academic Press, New York (1968).Google Scholar
- 2.A. N. Didenko, Microwave Power Engineering: Theory and Practice [in Russian], Nauka, Moscow (2003).Google Scholar
- 3.B. S. Petukhov, Heat Transfer and Resistance in Laminar Liquid Flow in Tubes [in Russian], Énergiya, Moscow (1987).Google Scholar
- 4.E. K. Kalinin and G. A. Dreitser, Nonstationary Convective Heat Transfer and Hydrodynamics in Channels. Progress in Science and Technology [in Russian], Énergiya, Moscow (1969).Google Scholar
- 5.M. D. Mikhailov, Nonstationary Heat and Mass Transfer in One-Dimensional Bodies [in Russian], Nauka i Tekhnika, Minsk (1969).Google Scholar
- 6.V. V. Salomatov, Nonlinear Heat and Mass Transfer — The Basis for Modern Technologies [in Russian], NGTU, Novosibirsk (2005).Google Scholar
- 7.I. S. Gradshtein and I. M. Ryzhik, Tables of Integrals, Sums, Series, and Products [in Russian], Nauka, Moscow (1971).Google Scholar
- 8.A. Erdelye, Asymptotic Expansions, Dover Publ., New York (1956).Google Scholar
- 10.I. Benicio, V. Dussan, and T. F. Irvine Jr., Laminar heat transfer in a round tube with radiating heat flux at the outer wall, in: Proc. 3rd Int. Heat Transfer Conf., Vol. 5, New York (1966), pp. 184–189.Google Scholar