Comparative Study of CALPUFF and CFD Modeling of Toxic Gas Dispersion in Mountainous Environments

Abstract

Verifying the pattern of toxic gas dispersion simulations under mountainous conditions is vital for emergency response and rescue. In this study, a comparative analysis is conducted between CALPUFF (California Puff Model) and CFD (Computational Fluid Dynamics) gas dispersion modeling focusing on the range of Semi-Lethal Concentration (LC50) and Immediate Danger to Life and Health Concentration (IDLH). To identify general dispersion patterns, a hypothetical pipeline breakout accident in a mountainous area is simulated and thirteen groups of simulation conditions are set up for the experiments, including calm wind (velocity less than 0.5 m/s) and winds from the east (E), south (S), west (W), and north (N) at velocities of 1, 2, and 3 m/s with a 1 arc-second degree SRTM data as terrain data. Comparative experiments show the diffusion patterns of the two models are essentially consistent, and the overall dispersion range deviation between two methods is within 266 m. The evaluation of CALPUFF’s adaptability for microscale mountainous environments indicates its potential use for high-sulfur gas fields and gas dispersion simulations in emergency scenarios.