Numerical investigation on heat transfer characteristics of a nuclear fuel rod

This paper deals with the numerical prediction of thermal performance characteristics of a cylindrical nuclear fuel element having nonuniform energy generation in axial direction. Accordingly, the two-dimensional heat conduction equation having a cosine variation of heat generation term in the axial direction, along with appropriate boundary conditions is solved using second order accurate finite difference schemes. The discretized equations in the form suitable to Line-by-Line method of solution procedure are solved employing the famous `Thomas Algorithm´ using an indigenously developed C code. The results are presented for a wide range of parameters - Aspect Ratio, A_r, Biot number, Bi and total heat generation parameter, Q_t in the form of comparison of the temperature profiles and maximum temperature for uniform and nonuniform energy generation. From the detailed discussion of the results it is concluded that, the maximum value of temperature attained in the fuel element for nonuniform volumetric energy generation is much higher than that of uniform volumetric energy generation. Also the non-uniform volumetric energy generation demands higher rate of energy dissipation from the surface of nuclear fuel element which is related to pumping power requirement of the coolant.