CFD modeling of fumes dispersion and propagation
Numerical simulation of atmospheric dispersion is used to study the propagation of gases, smoke or dust. It is therefore used to analyse the behaviour and assess the impact of atmospheric pollution of any kind. The approach can target a restricted zone of the order of a few metres or tens of metres, known as the near-field, or a much wider area.
Numerous phenomena can thus be modelled, such as the precise interaction of the emanations studied with the surrounding topography or infrastructure, the movement and dispersion of the cloud according to meteorological conditions (or ventilation in the case of a problem in a confined area), or chemical reactions with the ambient air. A CFD approach generally makes sense when a study using a Gaussian model does not provide the answers required.
The project below is an application of this type of modeling, with the aim of analysing the unsteady puffs of various exhausts around a ship.
Study of unsteady puffs of fumes around a ship
Context and issues
Ships with decks fitted out for passengers;
Emanations from several types of exhaust specific to the operation of the ship;
Are these emanations likely to inconvenience passengers at deck level?
Simulation of near-field atmospheric dispersion, with complex geometry;
Study of the local crossing of concentration thresholds, spatially and temporally: unsteady puff phenomena;
Coupling to atmospheric turbulent fluctuations;
Key physical concepts: atmospheric dispersion, fumes propagation, multiphase flows, atmospheric turbulence, unsteady fluctuations.
Project contributions
Development of the model in OpenFOAM: multiphase + DDES approach for turbulence;
Optimisation of the methodology for an industrial compromise between accuracy and calculation time;
Creation of meshes and simulations;
Comparison of results and calculation time with those of commercial software.
Technical environment
Linux and Windows, HPC cluster for simulations;
Programming in C/C++;
Meshing and CFD with OpenFOAM;
Visualisation with ParaView.