Challenges and objectives
Combustion represents 85% of primary energy in the world
It characterises a chemical reaction necessary for automotive and aeronautical motorisation systems, which plays a primary role in transforming materials, producing electricity, and heating our homes.
On the other hand, this physical phenomenon constitutes a source of atmospheric pollutant and significant CO2 emissions.
It is therefore necessary to understand more precisely the phenomena of combustion in order to reduce the energy consumption of the equipment and move towards the reduction of greenhouse gases.
Our design and engineering team has been investigating these issues for many years in order to develop predictive numerical simulation methods. It should be noted that in thirty years the polluting emissions (soot, nitrogen oxides, etc.) from the engines associated with this type of phenomenon have been reduced by 1,000.
The simulations make it possible to calculate the quantities of pollutants (CO2, CO, Nox, soot) produced during combustion, as well as to predict their distribution in a system in order to anticipate areas of concentration.
The models used will essentially depend on:
- Type of flame: whether or not fuels and oxidisers are mixed (premix flame or diffusion flame), and its turbulence (laminar flame or not)
- Level of precision: namely the necessary physics (radiation, CHT, etc.) and the power level of the computing machines (transient computation with several million elements, etc.).
The multi-physics approach can therefore quickly become a necessity, not only to correctly determine the combustion but also all its related phenomena. This makes it possible to know both the presence and the quantity of chemical substances (unburnt gases, pollutants) as well as the power released by combustion and the resulting temperature fields.
Other problems can be studied simultaneously, often of a geometric nature, such as flashbacks (for premixed flames) and the stabilisation of the flames thanks to a swirl effect. Indeed, these phenomena are closely linked to the complete or incomplete combustion of the reactants.
- Finite element modelling of the combustion phenomenon using the PaSR model
- Statistical modelling of combustion by PDF model
- Evaluation of temperature fields, hot spots, and wall temperatures
- Predictions of power released, unburnt gases, pollutants (CO2, CO, Nox, Soots)
- Analysis of recirculation zones
- Study of flashbacks (premixed flame)
- Multiphysics simulations via internal HPC (combustion, turbulence, radiation, CHT, monitoring of chemical species)
- Improved energy performance
Keywords: combustion, energy performance, multi-physical computations, statistical models, turbulence, radiation, unstructured mesh, HPC, thermomechanical dimensioning.
Tools: Ansys, OpenFOAM