Computational fluid dynamics or Gaussian – is there a right way to model gas dispersion ?
A. Tripathi, C. Souprayen, A. Stanley and N. Warrilow
https://doi.org/10.19124/ima.2018.001.26
Abstract
At present there are two main approaches to modelling gas dispersion within the process safety risk assessment arena. Historically the Gaussian approach has dominated, however, with the improvement of computing power available in relatively low-cost platforms, Computational Fluid Dynamics (CFD) has begun to challenge that dominance. Both approaches rely on a mathematical description of transport with advection-diffusion equations. However, there are a number of simplifications that are needed for analytical Gaussian solutions to be derived which are not needed for CFD solutions. The Gaussian approach often applies simplified flows over flat terrain, whereas CFD accounts for flow velocities and turbulence and their effects on mixing and can be applied in more complex three-dimensional environments. The questions this paper asks are: Is CFD modelling more mathematically correct than the Gaussian approach? And, Does the emergence of CFD into the mainstream pose an opportunity or threat? To answer these questions this paper will explore the previously mentioned differences between approaches.