Testing fireball diameter and duration of 227 gram cartridges containing isobutane

The aim of the work was to verify equations describing the diameter and duration of the fireball in relation to small tanks containing LPG. As a result of testing small, three-piece bayonet-type cartridges containing 227 g of isobutane, it was observed that the fireball parameters may vary significantly depending on the discharge direction of the medium. After the bottom gas discharge (BD) the fireball was found to have a significantly larger observed diameter than during the top discharge (TD), amounting on average to 4.58 and 3.63 m, respectively. An analysis of the maximum fireball diameter (rF), the total fireball duration (tF) and the time to reach the maximum fireball value (tMR) has shown that in the case of TD there is significantly greater convergence with relationships presented in the literature than is the case with BD. Comparing the static fireball models, it can be noticed that for the TD tests the rF values the closest to experiment are obtained in the case of the Williamson&Mann, Hasegawa Sato (1977), Lithiou&Maud (butane) and CCPS equations. In the case of BD tests, convergence with models is much lower, with the smallest error observed for the relationship presented by TNO (12.5%). The tMR and tF values calculated for the dynamic models of Martinsen & Marx and Pritchard are much shorter than those obtained in the experiment, and greater deviations may be noticed in the case of BD, especially in relation to the Pritchard model. The research showed that the fireball growth rate for the tested cartridges is much lower than predicted in the analysed models.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).