Thermal and Shock Dynamics Interactions in Vapor-Liquid Two-Phase Detonation

•Flame and thermal flow in vapor-liquid detonation are closely interconnected.•Residual fuel combustion reactions lead to multiple combustion and explosion phenomena.•Coupling development laws between the shock wave and temperature field are similar across different scales.•Transition from detonation to deflagration in vapor-liquid detonation are comprehensively elucidated.•Vapor-liquid detonation exhibits significant scale effects in range, time, and impact areas. A numerical model for vapor-liquid two-phase detonation is developed using computational fluid dynamics and combustion theory to address challenges in estimating transient dynamic behaviors. The study reveals that during initial detonation, the flame front closely aligns with the high-temperature flow field, then leading to immediate extinction beyond the cloud region. Nevertheless, the residual fuel continues to burn and diffuses with the high-temperature explosion products, resulting in multiple combustion-explosion phenomena. Additionally, the coupling mechanism between the shock wave and temperature field, particularly the transition pattern from detonation to deflagration is investigated by conducting simulations for detonations of fuel/air mixtures with different scales. It indicates that the vapor-liquid two-phase cloud detonation, irrespective of scale, manifests similar coupling development laws between temperature and pressure fields. Moreover, the propagation characteristics of the flame and overpressure are analyzed. An escalation in fuel mass corresponds to an expansion in detonation range, decoupling time, flame extent, and the areas of lethality and severe injury caused by shock waves. These observations collectively suggest the presence of significant scale effect in vapor-liquid two-phase cloud detonation. Overall, these findings enhance the understanding of energy utilization and the prevention of combustible cloud explosions involving such detonations.