Propensity for H2 flame wrinkling, acceleration and transition to detonation from side venting, rear venting and interaction with expansion waves

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The proposed research addresses the rapid shift of the energy sector in utilizing hydrogen fuel as an energy carrier. This fundamental transformation of the energy sector provides unique opportunities for Shell and Canada in the safe production and handling of clean hydrogen and associated technologies. The project addresses the explosion safety of hydrogen gas in scenarios of fuel leaks leading to combustible cloud formation in typical distribution and storage facilities with semi-enclosed spaces and venting capabilities. We study the effect of partial venting on the flame dynamics and the potential for rapid flame acceleration potentially leading to pressure wave amplification and transition to detonation. The need for this research is due to the absence of appropriate safety guidelines and the codes and standards that are required to prevent the flame acceleration and detonation transition. Such accident scenarios have been anecdotally documented in past large-scale trials and recent accidents in the industry, such as having occurred in 2019 at a hydrogen fueling station in Norway. The objective of the present research is to clarify the mechanisms that lead to flame acceleration in the presence of partial venting and to provide quantitative criteria for safe design of installation. A computational model will also be developed in order to obtain predictive capability of these phenomena. A suite of different experimental configurations with detailed flow visualization will permit to determine the unique physical mechanisms of flame acceleration that are peculiar to hydrogen-air mixtures in the presence of expansion waves. These experiments will be complemented by high-performance direct numerical simulations. Together, the experiments and simulations will be used generate scaling laws and validation bechmarks for engineering-type numerical models. The generation of these design tools addressing the explosion safety of hydrogen will be essential to the practicing engineer. The present research will also contribute to the training of highly-qualified personnel in the emerging energy sector activities involving hydrogen gas as energy carrier.