Small-scale BLEVE: Near-field aerial shock overpressure and impulse

This paper presents an investigation into one of the most damaging hazards associated with Boiling Liquid Expanding Vapor Explosion (BLEVE), specifically focusing on the near-field overpressure and impulse effects. Experiments were conducted at a small-scale to study the overpressure and impulse using aluminum tubes with a diameter of 50 mm and a length of 300 mm. The tubes were filled with pure propane liquid and vapor. The controlled variables, in this work included the failure pressure, the liquid fill level, and the weakened length along the tube top. These variables control the strength of the overpressure characterized by the peak overpressure amplitude, duration of this overpressure event, and the resultant impulse. Notably, these experiments at a small scale included experiments with a 100 % liquid fill level. This further confirmed that the vapor space is the main driver of the lead overpressure hazard. High-speed cameras and blast gauges effectively illustrated the progressive formation of the shock wave in both temporal and spatial dimensions. Furthermore, various predictive models available in the literature are discussed in this paper and new correlations were developed to quantify the overpressure duration and impulse. The current analysis aims to predict the potential consequences of overpressure events during a BLEVE. • The near-field vertical shock overpressure, duration, and impulse per unit area were studied using small-scale BLEVE experiments involving pure propane. • The vertical blast gauges recorded higher overpressure compared to side measurements. • The liquid fill level, weakened length, and failure pressure were adjusted one at a time to assess their individual contribution in blast overpressure. • High failure pressures, low liquid fill levels and long weakened lengths produced the highest peak overpressures. • The Friedman-Whitham spherical approach consistently estimates the near-field overpressure while duration and impulse were derived using a three-entry dimensionless correlation.