Performance Evaluation of Computational Fluid Dynamics and Gaussian Plume Models: Their Application in the Prairie Grass Project

Nowadays, industries and society are very concerned about pollution, well-being, health, air quality, and the possible negative effects of industrial emissions on a property’s surroundings. This gas dispersion is typically estimated with Gaussian Plume/Puff Models or software that uses these models with slight adjustments. The issue regarding these models is that they do not consider the surroundings’ particularities, for instance, when obstacles are present, and they require experimental data to adapt to specific scenarios. Therefore, the aim of this work is to validate the use of ANSYS Fluent ® 2022 R1 for modelling atmospheric gas dispersion. This validation is performed by comparing the ANSYS Fluent ® 2022 R1 findings to published experimental data, Gaussian Plume Models (GPM in this case corresponds to the application of the Gaussian Equation or Gaussian Fit, and does not correspond to a specific dispersion model), and ALOHA 5.4.7 software. A comparison between these three alternatives was not available in the literature. In terms of downwind dispersion, the findings of the three models are extremely comparable. However, ANSYS Fluent ® has a propensity to overestimate the concentration at higher heights. Validation using ANSYS Fluent ® in atmospheric gas dispersion applications enables confident results to be obtained in other scenarios. Differences in pollutant estimation between models are clear when studying more complex cases containing turbulence-inducing geometries. In these cases, CFD exhibits a more realistic description of the transport phenomena than the other models considered. The Prairie Grass Project is used as a tool to validate the CFD model, and to demonstrate its potential for more complex cases.