Fig. 1. Schematic of the 1D thermal diffusion model under the continuous heat source

Fig. 2. Loading time is 10 s, temperature distribution without heat loss and surface temperature field distribution when TDC is 80 mm²/s, and corresponding L_C and corresponding relative deviation δ_1D under different TDCs

Fig. 3. Schematic diagram of 1D thermal diffusion model considering surface convective heat transfer and when the TDC is 80 mm²/s and the loading time is 10 s, the temperature rise along the x direction under different thicknesses

Fig. 4. Relative deviation results of the 1D thermal diffusion model under different heat source loading times when h = 10 W/(m²·K)

Fig. 5. Schematic of the 2D thermal diffusion model under the continuous heat source with a radius of 100 μm

Fig. 6. With a continuous heat source of radius 100 μm, TDC of 100 mm²/s, and loading time of 20 s, surface temperature distribution under thermal insulation, isotherm plots of the dashed box area in Fig.(a) and temperature rise along the radial direction from the edge of the heat source and variation of L_C-2D with loading time

Fig. 7. Fitting result of L_C-2D and heat source loading time when the TDC is 100 mm²/s, and coefficients A and α

Fig. 8. Relative deviation results of the 2D thermal diffusion model simulation under different heat source loading times

Fig. 9. Schematic of the 2D thermal diffusion model with a continuous heat source of a radius of 100 μm when h=10 W/(m²·K), and temperature rise along the radial direction from the edge of the heat source under different thicknesses when the TDC is 100 mm²/s and loading time is 20 s

Fig. 10. Relative deviation results of the 2D thermal diffusion model under different heat source loading times when h=10 W/(m²·K)

Fig. 11. Schematic diagram of test setup