Soot Modelling and Radiative Transfer characterization for Low Emission Combustion Technology – SMART-LECT
The SMART-LECT project aims at sharing and enhancing advanced modelling for multiphysics numerical platforms, developed in order to improve the understanding and characterization of basic physicochemical mechanisms interacting in the combustors of aeronautical engines.This project is focused on the simultaneous description of nitrogen oxides emissions (NOx) and soot particle formation process, together with radiative heat transfers occuring within the combustors.
Nitrogen oxyde and soot formation - Determination of the temperature field within the combustor
The availability of validated numerical platforms is today considered as a key step in the design process of the future high performance combustors, in order to help reduce the impact of the civil air transport on the environment. Improved modelling will be achieved in the SMART-LECT project by the accurate prediction of the temperature field in the combustor, through the coupling of all modes of heat transfer (conduction, convection and radiation). As such, the SMART-LECT project aims at developing original and innovative modelling strategies, not restricted to a single field (combustion for example), but also taking into account all important and interacting physical processes.
Particular attention is paid to the validation of numerical tools developed in the SMART-LECT project, either by comparing the numerical results obtained by implementing different numerical techniques or theoretical models, either by comparing the numerical results with those from bases available experimental data. This validation, conducted as much for radiative transfers as the complex combustion chemistry, is first performed on basic test cases before being extended to more complex reactive flows, but also more representative of practical applications.
1 - The new spectroscopic databases were used to generate the high resolution spectra constituting the input data required to the construction of radiative models.
2 - in parallel, the modeling of combustion with complex chemistry dedicated to the soot and NOx formation, has been started with the objective to develop phenomenological, simple and accurate combustion models, improving the level of prediction of emissions of these major pollutants, while remaining compatible with the L.E.S approaches
3 - Preliminary work has been performed on the radiative transfer solvers (ASTRE and PRISSMA) in anticipation of the implementation of the new NB-MSR-SLMB radiative model
For the next period, the planned activity in the project SMART-LECT will be:
1 - The implementation of the NB-MSR-SLMB radiative heat transfer model in both [AVBP-PRISSMA] and [ASTRE-CEDRE] software multiphysics platforms
2 - The development of models of formation of NOx and soot and evaluation of elementary flames, laminar and turbulent.
3 - The determination of a more realistic combustion test case, enjoying a database as complete as possible facing the issues addressed in the SMART-LECTproject and implementation of the first numerical simulations on the selected combustion chamber geometry.
Joint scientific publications are of course scheduled, but at this stage of the project, which is now in its initial phase, they will not be immediately realized.
The SMART-LECT project aims at sharing and enhancing advanced modelling for multiphysics numerical platforms, developed in order to improve the understanding and characterization of basic physicochemical mechanisms interacting in the combustors of future aeronautical engines dedicated to the civil air transport. This research project is part of the approach jointly initiated by the Aero-engine manufacturers, Research centers and laboratories to ensure an appropriate control of pollutant emissions produced by civil air transport compatible with the future standards imposed at the european level (ACARE 2020 and FLIGHTPATH 2050). This project, exclusively theoretical and numerical, is focused on the development and validation of advanced models, allowing the simultaneous description of nitrogen oxides emissions (NOx) and soot particle formation process, together with radiative heat transfers occuring within the combustors. Temperature is indeed a key issue for industrial applications, since it has a significant impact on the formation of pollutants and on the lifetime of the components of a combustion chamber. The improvement of multiphysics numerical tools, allowing an accurate determination of the temperature field in the volume and at the wall of the combustion chamber, will be a major achievement of the SMART-LECT project. Multiphysics simulations will be carried out, coupling Large Eddy Simulation (LES) of the flow to the advanced models for thermal radiation and complex chemistry description, developed in the framework of this project. The target final application is a realistic combustor sector equipped with a staged-multipoint fuel injector manufactured by SNECMA. The numerical results will be compared to available measurements provided by ONERA to the other project partners. At the end of the project, a validated LES approach will be available for the simulation of complex and unsteady reactive turbulent flows, benefiting from advanced combustion modelling, including soot and NOx formation and accounting for thermal radiation.
As is the case for any development of accurate simulation methods for real applications, the SMART-LECT project will face the great challenge of reaching an acceptable compromise between high accuracy and reliability on one side, and computational cost and memory requirements on the other side.
Monsieur Daniel GAFFIÉ (ONERA) – Daniel.Gaffie@onera.fr
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
CETHIL CETHIL Centre de Thermique de Lyon
ARMINES ARMINES - RAPSODEE
Help of the ANR 597,984 euros
Beginning and duration of the scientific project: September 2012 - 48 Months