Characteristics of inclined negatively buoyant jet of dense gas leakage

Many industrial products generate or utilize toxic gases. Once a dense gas leak occurs, hazardous gases with negatively buoyant tend to accumulate in areas of human activity. The investigation on characteristics of inclined negatively buoyant jet (INBJ) of dense gas leakage can contribute to hazard assessment and effective elimination. This study explores the characteristics of dense gas leaks from inclined sources on the basis of high-speed schlieren imaging experiment and large eddy simulation. Two dense gases, carbon dioxide (CO2) and sulfur hexafluoride (SF6), were selected as pollutants. The results suggest that the characteristics of INBJ are primarily influenced by jet discharge angle and the densimetric Froude number, including the rise height, distance, and dilution ratio of the terminal and return points. The gas leakage with θ = 60° has the maximum dilution ratio, whereas the maximum distance of the return point is achieved at θ = 45°. A model is proposed to estimate the terminal rise height and distance of INBJ based on dimensional analysis. Finally, the semi-empirical formulas of the velocity distribution and dilution ratio were obtained. The reduced gravity of INBJ decreases exponentially from the source to the return point, while the X component of velocity decreases as a logistic function and the Z component of velocity decreases as a linear function. The findings of this study can contribute to the monitoring and assessing the impact of dense gas leakage.