Calculation of temperature fields in inlet regions of fuel element clusters in a liquid-metal coolant turbulent flow

The numerical solution of the problem concerning heat exchange of the initial section of the fuel element lattices subjected to the turbulent flow of the liquid-metal coolant is given. The density of the volumetric heat liberation in the fuel elements has been considered be uniform and the velocity profile has been considered to be stable. Only the longitudinal heat flows have been regarded. The calculations are performed within a wide range of the basic parameters: fuel element relative spacing - 1.02 (<=) S/d (<=) 2.0; equivalent fuel element heat conduction - 0.01 (<=) epsilon (<=) 10; the Pekle number - 100 (<=) Pe (<=) 2500. The calculation results are presented in the form of a general formula for estimations of the temperature fields and heat transfer on the initial section of the fuel element lattices. The coefficients used in the formula are shown in the form of nomograms. It has been established that the lengths of the initial thermal sections decrease with the increase of the spacing and equivalent heat conduction of the fuel elements and depend on the coolant flow conditions. For the laminar and rod flows, the length is directly proportional to the Pekle numbers, while for the turbulent flow, the length reaches its maximum in the Re function. The nomograms provide for determination of the length of the initial thermal sections within the considered ranges of variation of the parameters