Experimental study on the coupling of shock wave and temperature field during thermobaric explosive detonation in enclosed spaces

To investigate the coupled enhancement effect of blast shock waves and temperature from thermobaric explosives in confined spaces, explosion experiments were conducted using 100–400 g thermobaric charges within a confined building environment. Pressure sensors and thermocouples were employed to measure explosion pressure and temperature at various locations inside the enclosure, revealing the evolution characteristics and propagation laws of the shock wave and temperature field. The results indicate that internal explosions of thermobaric explosives exhibit significant secondary temperature rise and long duration features. A predictive model for initial temperature peak based on scaled distance is proposed. The TNT equivalent coefficient of the shock wave from thermobaric explosions exhibits a concave hyperbolic trend with increasing scaled distance, reaching a minimum value of 1.4 at a scaled distance of 1.7  m/kg1/3—corresponding to the boundary of the explosion fireball and the inflection point in the shock wave impulse growth rate. A two-stage predictive model for shock wave overpressure and impulse is established, which better characterizes the contributions of non-ideal detonation and aluminum powder afterburning effects in different spatial regions. Furthermore, a quasi-static pressure prediction model is developed based on pressure rise induced by explosive product expansion and post-combustion heating. As the charge mass increases from 200 g to 400 g, the quasi-static pressure rises from 2.27 to 4.18 times that of the 100 g charge, demonstrating a nonlinear increase due to the coupled effects of detonation products and post-combustion thermal augmentation