CFD-multi-energy comparison for modeling explosions

At industrial level, modeling the effects of an explosion can serve several purposes. In addition to accident reconstruction, it is used, for example, when carrying out the regulatory hazard studies required of all Seveso high threshold sites (facilities with the highest hazard potential due to the quantity of hazardous products stored). In addition, it may be essential for a manufacturer to ensure that his facility can withstand a given incidental explosion overpressure. In such cases, the purpose of calculating the effects of an explosion is to provide sizing criteria for the facilities to be protected (sizing of a control room, sizing of an offshore platform, etc.). Today's engineers have a wide range of methods at their disposal.

The last decade has seen a marked increase in the use of CFD (Computational Fluid Dynamics) tools. In theory, these tools are the most suitable for correctly modeling the explosion phenomenon.

The capabilities of a tool are of course important, but in practice, other considerations may come into play (e.g. not jeopardizing a previous ranking on the same site). If this were not the case, we would systematically resort to the CFD models with the greatest technical potential. So, faced with a given problem, the engineer needs to define the most appropriate approach, taking into account in particular :

• the customer's specific requirements in terms of cost and deadlines;

• the expected objectives of the study to be carried out ;

• the relevance and availability of any tools imposed by the customer;

• the ability of the tools to respond to the problem posed.

In this context, it can be difficult to choose the most appropriate modeling method. This choice must be made according to the needs and the objective set. The aim of this article is to shed light on the technical suitability of modeling tools for gas explosion issues. CFD modeling and the multi-energy approach are compared first from a theoretical point of view, then through a few case studies to identify the advantages and disadvantages of each approach.