Thermal diffusivtty measurements from a step function change in flux into a double layer infinite slab

Analysis of Transient Measurements Obtained for Thermal Insulations with the ORNL Flat Tester

“…The determinate error analysis assigned an uncertainty of =t= 0.03 K to steady-state temperature measurements and this is representative of the transient temperature measurements. Figure 2 illustrates the relationship between the measurement method and an analysis that uses an analytical expression for temperature as a function of time and position obtained by Halteman and Gernsh [5]. The mathematical formulation of the boundary value problem and the solution for temperature as a function of time at the interface between screen and test specimen are shown in Table 3.…”

Non-Steady-State Behavior of Thermal Insulations

“…Figure 2 illustrates the two-region formation that is being used in the analysis. An infinite-series solution for the problem was obtained [8] for a step-change in the heat flux at one boundary of the heater. Their analytical solution is for a boundary value problem that is slightly different from the volumetric heat generation process actually present in the screen.…”