Size effect on the thermal response of aluminum profiles: Experimental and numerical simulation study

This study analyzes the thermal response characteristics of aluminum profile structures of various sizes under different heating conditions through a combination of small-scale and large-scale experiments. A threedimensional numerical model was used to simulate heat transfer behavior across different sizes and heating scenarios for small-sized aluminum profiles. In the case of large-sized aluminum profiles, a two-dimensional numerical model incorporating coupled phase transitions was employed to investigate the effects of size on their thermal response in high-temperature environments. The results for small-sized aluminum profiles indicate that, for a fixed ratio of heating size to sample size, the maximum temperature at the backfire surface of the aluminum profiles increases with size under identical heating conditions. In contrast, the average temperature at the backfire surface remains relatively stable. This observation, validated by numerical simulations and theoretical analysis, highlights the influence of heating and sample size on the thermal response characteristics. For large-sized aluminum profiles, it was observed that their refractory properties varied with size under consistent heating conditions, with integrity failure time decreasing as the structural size increased. The reliability of the two-dimensional numerical simulations was confirmed by comparison with experimental data. Further investigations extended the analysis to a broader range of aluminum profile sizes and size ratios, revealing a logarithmic relationship between the integrity failure time of the profiles and their structural size and heating dimensions.