A numerical solution based parameter estimation method for flash thermal diffusivity measurements

A data reduction method based on numerical solutions of the heat conduction equation has been developed for obtaining thermal diffusivity values from thermal flash measurements. Using the new method, the computed evolution in temperature is fitted to the measured temperature evolution instead of using the t1/2 point alone, as is done in many other analyzes. The numerical solutions used are based on the finite-difference technique applied to the heat conduction equation including all the boundary conditions. A nonlinear least-squares regression technique is used to estimate simultaneously the thermal diffusivity, the heat transfer coefficient and the absorbed energy. Also, the effect of a finite pulse-width can be corrected without knowing the exact shape of the heat pulse.