Similarity criteria for laser‑induced thermo‑mechanical responses of metal plates under high‑speed airflow with fluid-thermal-structural coupling

This paper investigates the similarity criteria and scaling strategies for the laser-induced thermo-mechanical responses of metal plates under high-speed airflow, where strong fluid-thermal-structural coupling renders existing similarity laws inapplicable. Using Buckingham’s Π theorem, We derive fourteen dimensionless parameters, including six for thermal response and eight for mechanical response, and reveal that the criteria for aerodynamic heat and aerodynamic force are inherently incompatible. To resolve this conflict, we propose two approximate scaling strategies: strategy ① prioritizes the aerodynamic heat criterion, making it suitable when thermal effects dominate; strategy ② prioritizes the aerodynamic force criterion, making it suitable when mechanical effects dominate. Numerical simulations validate that, under the appropriate strategy, the scaled model predicts temperature with an error of less than 1 % and deformation with an error of less than 4 % compared to the full-scale model. Furthermore, we establish an error map for the characteristic thickness ratio and identify a critical value of 12/400 that determines the superior scaling strategy. This work provides a foundational framework for conducting cost-effective scaled laser irradiation experiments in high-speed wind tunnels, which were previously impractical due to scaling conflicts.