Boiling heat transfer under forced convection of sodium

As the basic research on the heat transfer concerning the safety of sodium-cooled fast neutron reactors, the authors have carried out the research on the boiling heat transfer under the natural convection of sodium. Moreover, the basic research on the non-boiling and boiling heat transfer under forced convection in steady and unsteady states is planned. As the unsteady state, the transient phenomena accompanying the rapid increase of heat generation of a heater and the rapid decrease of sodium flow rate are considered. First, as the research on the boiling heat transfer under the forced convection of sodium, the non-boiling heat transfer in the heat flux below the point of initial bubble generation was examined. It is the interesting problem to examine experimentally the heat transfer characteristics of sodium over the whole range of laminar flow, transition and turbulent flow regions. The experimental apparatuses and the experimental method are explained. The result of experiment is shown in relation to Nusselt number and P'eclet number. In the experiment by the authors, the effect of heat conduction in axial direction was negligibly small. In liquid sodium also, in the transition region from laminar flow to turbulent flow, the tendency similar to the forced convection heat transfer obtained with mercury by Petukhov was shown. (Kako, I