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Conference Article: An analytical method of evaluating the effect of rod displacement on circumferential temperature and heat flux distributions -- two and three dimensional treatments

Hishida, Hisashi (Mitsubishi Atomic Power Industries, Inc., Tokyo (Japan))

Abstract

An analytical method of evaluating the circumferential variations of temperature and heat flux fields inside and around a displaced fuel rod in triangular rod bundles in turbulent flow is presented with illustrative examples in Section A. The analysis mainly consists of deriving the simultaneous solutions of a set of heat conduction equations for fuel, cladding and coolant under the assumption of fully developed flow and heat transfer conditions. The local coolant velocity distribution, which is necessary for deriving the temperature field in coolant, is determined by solving the Navier Stokes equation and the turbulent mixing of coolant is taken into consideration. The results show that the circumferential variations in temperature field and heat flux field on the outer surface of cladding become more appreciable with the lower P/D ratio and with increase in fuel rod displacement. In Section B, the extension of the two-dimensional method developed in Section A to a three-dimensional method is discussed with brief explanations on the derivation of the heat conduction equation and its solution in the form of Fourier series expansion. Some applicability of the solution is suggested.

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key words: flow models; fuel cans; fuel rods; heat transfer; navier-stokes equation; three-dimensional calculations; two-dimensional calculations; variations
Reference:
Summary report of a panel meeting held in Karlsruhe, 22-24 November 1973 on the recommendation of the International Working Group on Fast Reactors. 1974. p. 133-142
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--166, pp:194-205