Steady integral plume model for rapid prediction of high-speed hydrogen leakage and venting

Existing integral models for hydrogen plumes are limited by empirically prescribed parameters, parameter coupling, and restricted applicability. For high-speed hydrogen plumes issuing from small orifices, a simplified MTT formulation is developed using a self-similar inlet, reduced parameter set, calibration over a broad operating range, and inlet-condition-based closure, with extension to a Frenet coordinate system. Linear regressions relate the velocity-to-concentration width ratio and momentum-entrainment correction coefficient directly to inlet conditions. Calibration and independent validation support the emergence of a self-similar state within the zone of flow establishment, with satisfactory agreement obtained for vertical and inclined plumes. The model is substantially more computationally efficient than CFD, enabling rapid estimation of hydrogen dispersion distances, venting directions, and safety clearances.