Periodic Reporting for period 2 - ESTiMatE (Emissions SooT ModEl)
Okres sprawozdawczy: 2020-05-01 do 2022-10-31
The demand for air travel is increasing as the world becomes more interconnected and interdependent and as a consequence, the aviation industry continues to produce greenhouse gas emissions and pollutants like soot, which contribute to climate change. Among the non-CO2 effects caused by aviation, the production of soot, a by-product of burning carbon-based fuels, is considered the second largest contributor to global warming and contrail formation, after CO2.
In this context, the project ESTiMatE was proposed in view of future emission regulations for smoke and particulate limitations in lean burn aero-engine architectures and addresses the fundamental issue of soot formation for kerosene-type fuels under lean burn conditions.
ESTiMatE is dedicated to the development of advanced soot models and its application in combustion simulations for the prediction of soot formation from oxidation to particle formation at conditions of relevance for aeroengines. Having advanced and reliable models for high-fidelity simulations is fundamental, since Computational Fluid Dynamics (CFD) is a key element for the design of next generation low-emissions engines, leading to important savings in time and cost.
To achieve the ambition introduced above, ESTiMatE was built to fulfil the following specific objectives:
- Identification of the main precursors and polycyclic aromatic hydrocarbons (PAHs) for soot formation from the analysis of chemical kinetics of kerosene-like surrogates.
- Identification of chemical paths for soot formation from precursors and PAHs.
- Generation of detailed and reduced chemical kinetics for fuel oxidation that also account for soot chemistry.
- Development of particle size distribution models to represent the dynamics of soot.
- Integration of the developed chemical kinetics and soot models into different turbulent combustion models.
- Development of a primary breakup model for air blast injectors based on high-fidelity numerical simulations.
- Development of reference experiments for combustion from laminar to turbulent conditions to generate specific data for model development and validation.
- Assessment of models for the prediction of soot under conditions relevant to aero engine combustors.
During the project, these objectives have been successfully achieved providing valuable results for the modelling of soot formation from nucleation to particle formation, oxidation and dynamics. In particular, a new chemical mechanism that accurately reproduces the chemistry involved in the soot formation was generated and applied along with advanced turbulent combustion models to the complex simulation of turbulent flames with a high degree of agreement in comparison to experiments. In addition, a primary breakup model for air blast injectors was developed, tested and validated using Lagrangian sprays.
As a consequence, the highly advanced models envisaged in this project have enabled a detailed description of the combustion and emission-formation phenomena in the complex environment of the combustion chamber of aeroengines. On the other hand, such models are being used to design engines with lower pollutant emissions, with the subsequent benefits for both the environment and the society.
In this context, the project ESTiMatE was proposed in view of future emission regulations for smoke and particulate limitations in lean burn aero-engine architectures and addresses the fundamental issue of soot formation for kerosene-type fuels under lean burn conditions.
ESTiMatE is dedicated to the development of advanced soot models and its application in combustion simulations for the prediction of soot formation from oxidation to particle formation at conditions of relevance for aeroengines. Having advanced and reliable models for high-fidelity simulations is fundamental, since Computational Fluid Dynamics (CFD) is a key element for the design of next generation low-emissions engines, leading to important savings in time and cost.
To achieve the ambition introduced above, ESTiMatE was built to fulfil the following specific objectives:
- Identification of the main precursors and polycyclic aromatic hydrocarbons (PAHs) for soot formation from the analysis of chemical kinetics of kerosene-like surrogates.
- Identification of chemical paths for soot formation from precursors and PAHs.
- Generation of detailed and reduced chemical kinetics for fuel oxidation that also account for soot chemistry.
- Development of particle size distribution models to represent the dynamics of soot.
- Integration of the developed chemical kinetics and soot models into different turbulent combustion models.
- Development of a primary breakup model for air blast injectors based on high-fidelity numerical simulations.
- Development of reference experiments for combustion from laminar to turbulent conditions to generate specific data for model development and validation.
- Assessment of models for the prediction of soot under conditions relevant to aero engine combustors.
During the project, these objectives have been successfully achieved providing valuable results for the modelling of soot formation from nucleation to particle formation, oxidation and dynamics. In particular, a new chemical mechanism that accurately reproduces the chemistry involved in the soot formation was generated and applied along with advanced turbulent combustion models to the complex simulation of turbulent flames with a high degree of agreement in comparison to experiments. In addition, a primary breakup model for air blast injectors was developed, tested and validated using Lagrangian sprays.
As a consequence, the highly advanced models envisaged in this project have enabled a detailed description of the combustion and emission-formation phenomena in the complex environment of the combustion chamber of aeroengines. On the other hand, such models are being used to design engines with lower pollutant emissions, with the subsequent benefits for both the environment and the society.
During the project, remarkable achievements have been made towards the generation of new knowledge and capacities:
- Generation of chemical mechanisms able to accurately predict the PAHs and soot precursors in which complex chemical paths are involved.
- Integration of soot models into combustion models: different approaches have been devised in order to reduce the computational cost and applied along with different combustion models to evaluate the influence of the combustion model on soot predictions.
- Analysis of the computational tools to reproduce laminar flames: a special attention has been given to the laminar configurations since, first, they allow to analyse the capabilities of the chemical and soot models without the uncertainty introduced by turbulence and, second, many models are based on laminar flames.
- Application of the models to turbulent configurations: several configurations widely studied in the literature have been simulated for which excellent results have been achieved.
- Optimization of the generated software.
- Generation of large databases of experimental measurements: a large database of experiments and high fidelity simulation datasets has been generated.
- Generation of a new model for atomization in air-blast atomizers: a great effort has been dedicated to the generation of an atomization model through the analysis of DNS results.
- Generation of chemical mechanisms able to accurately predict the PAHs and soot precursors in which complex chemical paths are involved.
- Integration of soot models into combustion models: different approaches have been devised in order to reduce the computational cost and applied along with different combustion models to evaluate the influence of the combustion model on soot predictions.
- Analysis of the computational tools to reproduce laminar flames: a special attention has been given to the laminar configurations since, first, they allow to analyse the capabilities of the chemical and soot models without the uncertainty introduced by turbulence and, second, many models are based on laminar flames.
- Application of the models to turbulent configurations: several configurations widely studied in the literature have been simulated for which excellent results have been achieved.
- Optimization of the generated software.
- Generation of large databases of experimental measurements: a large database of experiments and high fidelity simulation datasets has been generated.
- Generation of a new model for atomization in air-blast atomizers: a great effort has been dedicated to the generation of an atomization model through the analysis of DNS results.
ESTiMatE is focused on the study of soot formation in aeronautical burners using advanced soot models for particle size distributions. The project results have shed light into the influence of the combustion model and the treatment of turbulence chemistry interactions on the prediction capabilities of the soot models in terms of soot volume fraction, soot volume density and particle size distributions. The validation and assessment of the models has come from the definition of dedicated experiments with an increased level of complexity. The project has included the development of a reaction mechanism for the fuel oxidation and soot precursors for a fuel surrogate. One of the impacts of the project is the development of advanced software for pollutant formation that can be used with confidence to speed up the combustion design process.
Beyond from the mentioned scientific benefits of the project, in terms of the socio-economic impact it can be said that ESTiMatE has contributed to:
- Improve the innovation capacity and the integration of new knowledge: efficient and environmentally sustainable engine development demands for advanced model developments. The development of such activity requires a multidisciplinary approach for the integration of different fundamental disciplines, such as chemistry, fluid mechanics and thermal design.
- Reduction of engine development lifecycle: investment in upstream technologies, such as the development of numerical tools, models and algorithms is becoming a key ingredient to improve the competitiveness of the European industry.
- Strengthening the European competitiveness of the aeronautical sector: the aviation sector is a very valuable asset which enables the development of sustainable and competitive products and services while maintaining and creating high-skilled jobs in Europe. Through technological innovation, the aeronautics industry plays a key role to reduce the environmental impact of civil aviation. In this context, ESTiMatE engages R&D Centres, Academia and Industry bringing together a network from the entire European aeronautics High Performance Computing (HPC) Combustion industry value chain into a sustained collaboration effort which will greatly improve the resilience and competitiveness of the European aeronautics industry.
- Strengthening the European competitiveness on HPC technologies: the project addressed the development of large-scale simulations including high-fidelity models not only to characterize the reacting flow field of a real aeroengine combustor but also to predict pollutant emissions and soot with confidence. The use of HPC using high-fidelity numerical simulations is fundamental to investigate the combustion characteristics of fuels in practical combustors.
Beyond from the mentioned scientific benefits of the project, in terms of the socio-economic impact it can be said that ESTiMatE has contributed to:
- Improve the innovation capacity and the integration of new knowledge: efficient and environmentally sustainable engine development demands for advanced model developments. The development of such activity requires a multidisciplinary approach for the integration of different fundamental disciplines, such as chemistry, fluid mechanics and thermal design.
- Reduction of engine development lifecycle: investment in upstream technologies, such as the development of numerical tools, models and algorithms is becoming a key ingredient to improve the competitiveness of the European industry.
- Strengthening the European competitiveness of the aeronautical sector: the aviation sector is a very valuable asset which enables the development of sustainable and competitive products and services while maintaining and creating high-skilled jobs in Europe. Through technological innovation, the aeronautics industry plays a key role to reduce the environmental impact of civil aviation. In this context, ESTiMatE engages R&D Centres, Academia and Industry bringing together a network from the entire European aeronautics High Performance Computing (HPC) Combustion industry value chain into a sustained collaboration effort which will greatly improve the resilience and competitiveness of the European aeronautics industry.
- Strengthening the European competitiveness on HPC technologies: the project addressed the development of large-scale simulations including high-fidelity models not only to characterize the reacting flow field of a real aeroengine combustor but also to predict pollutant emissions and soot with confidence. The use of HPC using high-fidelity numerical simulations is fundamental to investigate the combustion characteristics of fuels in practical combustors.