Data reduction by an approximate thermal diffusion solution
J. M. Kendall · 1975
A solution of the differential equations for a one dimensional time dependent heat conduction problem is used to generate approximate transfer functions for the response for the geometry defined by the boundary conditions.The resulting approximate transfer functions are used to develop a method for calculating the transient surface conditions of simulated nuclear fuel rods from known transient internal conditions.The method is applied to example cases based on the results of selected experiments.The primary advantages of the method are computational speed and stability.The principal limitations are the assumptions of constant thermal properties (independent of temperature) to obtain a linear system, and uncertainties associated with the approximate forms of transfer functions.The approximation functions are not unique; the specific functions discussed in this report were generated based on quasi-steady state considerations.For the parameters studied, the approximation for the measured temperature/surface heat flux transfer function is the most limiting.Further refinements of the approximations could be expected to reduce this source of error.