HEAT TRANSFER IN A LIQUID METAL UPFLOW IN A PIPE WITH MIXED TURBULENT CONVECTION COMPLICATED BY THE INFLUENCE OF MAGNETIC FIELD

The results of a study of heat transfer in the case of a liquid metal upfl ow in a vertical heated pipe without a magnetic fi eld, as well as in the presence of longitudinal or transverse magnetic fi elds, are presented. With the use of microthermocouple probes, profi les of the averaged velocity and of temperature, distribution of local heat transfer coeffi cients, and fl uctuation characteristics of temperature in the fl ow were obtained. In the absence of a magnetic fi eld, a decrease in the heat transfer coeffi cients compared to a purely turbulent level was found, which agrees qualitatively with the general laws governing heat transfer in mixed convection for nonmetals. Studies carried out in a longitudinal magnetic fi eld have shown that in the confi guration of an upward fl ow too, one cannot avoid the infl uence of thermogravitational convection, which only increases in a laminarized fl ow, leading to an increase in instabilities and to the appearance of low-frequency velocity and temperature pulsations. In a transverse magnetic fi eld with an upward fl ow, interesting eff ects were also revealed, associated with the action of electromagnetic forces and thermogravitational convection on the hydrodynamics of averaged fl ow and fl uctuation characteristics of heat transfer
   
Author:  N. A. Luchinkin, N. G. Razuvanov, O. N. Polyanskay, M. A. Sokolov, E. A. Burdyukov
Keywords:  liquid metals, hydrodynamics, heat transfer, magnetic fi eld, thermogravitational convection
Page:  1548