Numerical Study on the Gas Leakage and Dispersion at the Street Intersection of a Building Group.

Accidents involving natural gas leakage and dispersion pose a significant threat to human life and property. This threat is especially relevant at the street intersection at which dense buildings, heavy traffic flow, and complex underground pipe networks meet. Scholars have conducted numerous studies on gas leakage and dispersion, but investigations of natural gas leakage and dispersion at the street intersection of a building group are not in-depth. In this paper, we presented a three-dimensional (3D) physical model based on the Computational Fluid Dynamic (CFD) methodology to study the natural gas leakage and dispersion at the street intersection of a building group. We validated the CFD methodology applied in the research based on the data from the field tests and wind tunnel experiments. Then, we simulated and analyzed the pressure, wind, and concentration of natural gas dispersion at the street intersection. The simulation results showed that vortex regions, low-pressure zones, and a building group effect could cause a build-up of natural gas concentration under perpendicular wind direction conditions. In addition, the area of hazardous region tended to increase first and then drop with the dispersion height. In the case of this study, the maximum area of hazardous region is 200 m2 located in the height of 55 m, which is the middle plane in the computational domain. The results in the paper can provide scientific references for the safe operation and emergency-management decisions of municipal gas. [ABSTRACT FROM AUTHOR]