Based on thermoelectric generators (TEGs), an aerodynamic heat energy recovery system for vehicle is proposed. A mathematical model describing the energy conversion law of the system is established, and the integrated calculation method which combined aerodynamic heating and thermoelectric (TE) conversion is given. Furthermore, the influences of the typical flight Mach number, flight altitudes and the length of TE legs on the energy conversion behavior of energy recovery systems are investigated. The performance of the energy recovery system is analyzed and evaluated. The results show that, the decrease of flight altitude and the increase of Mach number will obviously improve the performance of the heat energy recovery system with TEGs. The increase of leg length will increase the temperature of the hot end of TEGs and reduce the heat absorbed at the hot end. When the external load, Mach number and flight altitude is fixed, there exists an optimal length of legs corresponding to the maximum output power and maximum conversion efficiency of the system. The results will have significant positive impact on thermal protection and management of supersonic/hypersonic vehicles.

The study used linearly and circularly polarized femtosecond pulsed lasers to irradiate a Ta₂O₅/SiO₂ film. Firstly, the damage thresholds of the film for linearly and circularly polarized femtosecond pulsed lasers were measured in 1-on-1 mode. The results showed that the damage threshold (1.70 J/cm²) under a circularly polarized laser was higher than that (1.68 J/cm²) under a linearly polarized laser. For femtosecond lasers, the multi-photon ionization cross-section under circular polarization was lower than that under linear polarization. The lower ionization rate under circular polarization led to a higher damage threshold compared to the case under linear polarization. Secondly, the damage morphology of the film irradiated by linearly and circularly polarized femtosecond lasers was observed by microscope. The damage caused by linearly polarized laser was more evident than that caused by the circularly polarized laser. Finally, the damage thresholds induced by linearly and circularly polarized femtosecond pulsed lasers were measured in S-on-1 (S = 2, 5, and 10) mode. For the same S value (2, 5, or 10), the damage threshold under the circularly polarized laser was higher than that under the linearly polarized laser. The damage thresholds under two polarized laser pulses decreased with an increase in the number of laser shots, indicating that repeated laser pulses had a cumulative effect on the damage of the film.

To improve the laser-induced damage resistance of 7075 aluminum alloy, a typical aerospace material, a laser-resistant coating material for the surface of 7075 aluminum alloy was prepared in this paper. The performance of 7075 aluminum alloy coated with this coating was analyzed and tested by combining numerical simulation and experimental verification. The test results show that under the same laser irradiation conditions and geometric dimensions, the breakdown time of 7075 aluminum alloy coated with the laser-resistant coating is prolonged by 541.6%, and its laser-induced damage resistance is significantly improved.

To improve the laser-induced damage resistance of 7075 aluminum alloy, a typical aerospace material, a laser-resistant coating material for the surface of 7075 aluminum alloy was prepared in this paper. The performance of 7075 aluminum alloy coated with this coating was analyzed and tested by combining numerical simulation and experimental verification. The test results show that under the same laser irradiation conditions and geometric dimensions, the breakdown time of 7075 aluminum alloy coated with the laser-resistant coating is prolonged by 541.6%, and its laser-induced damage resistance is significantly improved.

Laser irradiation, as a high-energy input, induces a rapid temperature rise on a structure’s surface, resulting in a localized stress concentration, which is one of the key elements in catastrophic failure. Accurate structural health monitoring of plates should take stress distribution into account. In this paper, we present a theoretical model for determining the stress state of a plate under combined laser radiation and airflow, using temperature values from several discrete measurement points as input. First, a fitting function was proposed based on data-driven thermal analysis, which is utilized to acquire the temperature distribution on the whole surface. The stress state near the area of the laser radiation was then calculated using a theoretical model based on the elasticity theory of an axis-symmetric problem. With the incorporation of the data-driven method, the model is then extended from a baseline analytical model to account for three-dimensional heat-conduction effects and the nonlinear temperature dependence of thermophysical properties. The effectiveness and precision of the proposed model were verified by coupled thermal-mechanical simulations. The current work can provide substantial support for developing a structural health monitoring system for aerospace structures exposed to laser radiation.

To address the difficulty in continuously and accurately quantifying the time-dependent damage size of targets under coupled laser–tangential airflow action, this paper proposes a piecewise exponential damage inversion modeling method combining deep learning and physical driving. A synchronous laser–tangential airflow experimental platform is built, and 0–5 s damage time-series images are collected to construct a dataset. The YOLO26 real-time visual detection network is selected to realize automatic identification of ablation molten spot regions, with model precision of 0.984, mAP@0.5:0.95 = 0.966, and single-frame inference time of 27.6 ms. Relying on a self-developed visual interactive program, batch time-series image automatic recognition and size conversion are completed, and 1.6–5.0 s is determined as the reliable quantitative interval. Based on the effective data in this interval, the competitive coupling effect between airflow shear-induced melting enhancement and convective cooling is analyzed. A piecewise exponential evolution model containing a quadratic modulation term of tangential airflow is constructed, which well describes the three-stage nonlinear law of damage “initiation–expansion–stabilization”. A genetic algorithm is used to complete global parameter fitting under multiple working conditions. The average relative errors of the model for damage length and width are both lower than 2.1%, RMSE is less than 0.7 mm, MAE is less than 0.52 mm, and $R^2$ is higher than 0.994. This work can provide a theoretical basis and technical scheme for quantitative time-series analysis of damage in metal targets irradiated by high-energy lasers.