Soutenance de thèse de El Mehdi Laamarti

Abstract : 
One of the critical concerns for modern industry—particularly within the chemical and petroleum sectors—is the investigation of accidents caused by Boiling Liquid Expanding Vapor Explosions (BLEVEs). A BLEVE is a violent thermomechanical physical explosion that occurs when a pressure-liquefied gas (PLG), such as propane or butane, undergoes vapor expansion and boiling liquid following total loss of containment. Although storing PLGs under pressure offers an efficient means of reducing required volume, their transportation and handling introduce significant risk, with accidental BLEVEs capable of causing human casualties, severe environmental damage, and extensive structural losses. To mitigate the catastrophic effects of this phenomenon, a thorough physical understanding of its associated hazards is essential to develop a reliable predictive model. This research aims to deepen the understanding of BLEVE by integrating both experimental and computational approaches to enhance hazard prediction and risk mitigation. The focus will be on analyzing near-field blast wave formation, the ground load, the internal and boiling dynamics and how the opening dynamics do influence these hazards.
Experimentally small-scale experiments were conducted using aluminum tubes, systematically varying key parameters such as liquid fill level, failure pressure, and weakened vessel length. High-speed imaging and pressure measurements were used to characterize vessel rupture dynamics, near-field shock overpressure, and ground loading effects, providing new insight into the roles of liquid–vapor interactions and opening dynamics in determining BLEVE severity.
Complementary numerical simulations, performed with Ansys Fluent, replicated internal boiling and external blast propagation, bridging knowledge gaps not accessible through experiments alone.
Overall, the findings refine the definition of a BLEVE, clarify the conditions under which it occurs, and propose predictive correlations that strengthen industrial safety protocols, support risk assessment, and guide the design of safer pressurized storage systems.