Modeling rapid expansion of superheated liquids in energy storage infrastructure: pressure impulse and mechanical consequences

The large-scale use of liquefied energy carriers increases the need to assess transient hazards during storage and transport. Rapid depressurization of superheated liquids can trigger flash boiling and compressible two-phase expansion, producing strong pressure transients and impulse loading that govern vessel-failure consequences. This study develops a thermodynamically consistent framework to model rapid superheated-liquid expansion. A spherically symmetric compressible multiphase model is established, where boiling onset is initialized at the thermodynamic superheat limit rather than the commonly assumed saturation state. High-order finite differences with Level Set and Ghost Fluid methods are used to resolve the interface dynamics and pressure evolution. Results show that the initial thermodynamic state strongly affects peak pressure and pressure impulse, and saturation-based initialization overpredicts the driving impulse, yields overly conservative estimates. The predicted impulse is further coupled with fragment inertia to estimate fragment velocities in BLEVE scenarios. Here, BLEVE denotes catastrophic vessel failure of a pressurized liquefied fluid followed by rapid flashing and volumetric expansion. The proposed approach offers a physically grounded and computationally efficient tool for safety assessment and design of energy storage and transportation systems.