Numerical exploration and modelling of novel environmentally friendly combustion technique: droplet-laden MILD combustion
Lead Research Organisation:
Newcastle University
Department Name: Sch of Engineering
Abstract
A small reduction in NOx emission per kilo-watt of generated power will have a significant reduction in environmental impact of combustion used for power generation. The MILD (Moderate or Intense Low-Oxygen Dilution) combustion technique offers an opportunity to drastically reduce emissions while improving thermal efficiency of furnaces and boil-ers. In gas turbines, though overall fuel-air mixture is fuel-lean and MILD combustion is not directly applicable, fuel-rich regions in the primary zone of the combustor exhibit localised MILD regimes, particularly for liquid fuel operation How-ever, the physical and chemical intricacies of this novel technique are not well understood and thus identifying key con-trol parameters for using this technique for power generation and industrial processes over wide range of conditions is challenging. This project aims to provide a step change in physical understanding and modelling of this combustion technique and to identify key control parameters. The aim is to investigate MILD combustion of high calorific value gaseous and liquid fuels for practical application using Direct Numerical Simulations (DNS) and Large Eddy Simula-tions (LES), with high-fidelity mathematical description for physical and chemical processes involved. The droplets of liquid fuel spray will be tracked using the Lagrangian approach while the gas phase is treated using the Eulerian ap-proach for the simulations.
The effects of droplet diameter, equivalence ratio (both for gaseous and liquid fuels), extent of dilution by combustion products, volatility (by considering different fuels), turbulence intensity and its length scale on the burning rate, flame structure (in terms of chemical reaction pathways analysis and flame and flow topologies) and pollutants formation will be analysed based on a judicious parametric analysis based on three-dimensional detailed chemistry DNS data. In this project, the fundamental physical understanding extracted from DNS data will be utilised to develop high-fidelity models for engineering Computational Fluid Dynamics (CFD)-based simulations to identify key control parameters using LES after validating these models against the available experimental results. This project will provide (1) a ro-bust modelling framework for MILD combustion technique, which would be a cost-effective reliable tool for designing energy-efficient and clean gas turbines and industrial furnaces and (2) the key control parameters identified can help to design retro-fit "greener" combustion systems.
The effects of droplet diameter, equivalence ratio (both for gaseous and liquid fuels), extent of dilution by combustion products, volatility (by considering different fuels), turbulence intensity and its length scale on the burning rate, flame structure (in terms of chemical reaction pathways analysis and flame and flow topologies) and pollutants formation will be analysed based on a judicious parametric analysis based on three-dimensional detailed chemistry DNS data. In this project, the fundamental physical understanding extracted from DNS data will be utilised to develop high-fidelity models for engineering Computational Fluid Dynamics (CFD)-based simulations to identify key control parameters using LES after validating these models against the available experimental results. This project will provide (1) a ro-bust modelling framework for MILD combustion technique, which would be a cost-effective reliable tool for designing energy-efficient and clean gas turbines and industrial furnaces and (2) the key control parameters identified can help to design retro-fit "greener" combustion systems.
Planned Impact
The major impacts of this research endeavour are summarised as follows:
(i) Development of fundamental understanding and modelling of turbulent droplet-laden MILD combustion:
The research outcomes will be disseminated through participation in international conferences (e.g. Int. Combust. Symp., Eur. Combust. Meeting, Numer. Combust. Conf. etc.) and publication in reputed scientific journals (e.g. Combust. Flame, Phys. Fluids, Combust. Sci. Technol., Combust. Theor. Modell. etc.). Moreover, the models developed during the course of this project will enhance the knowledge-base of turbulent reacting flows and predictive capability of engineering simulations, which in turn will play a key role in the design-cycle of next generation energy-efficient and environment friendly combustors. The DNS and LES databases resulting from the proposed research programme will be made available to other interested researchers upon request. The Research Associates (RA) will manage a website for data-exchange and documentation, and important results will be made available for public download. A workshop on MILD combustion will be organised at the conclusion of the project to maximise the chances of technical dissemination, and to attract the attention of relevant industrial sectors.
(ii) IC-engine and gas turbine manufacturers:
Improving the predictive abilities of MILD combustion of droplet-laden mixtures will be of great benefit to these industries for the development of new generation energy-efficient and environment friendly combustors. Industrial colleagues will be invited to attend half-yearly progress meetings and the planned workshop so that they remain aware of the development of the proposed research programme and their feedback will be taken on board during the course of the proposed research programme. A website will be maintained throughout the proposed work with information on data-exchange and documentation, and specific results will be made available for public download along with the latest findings in open literature. It will therefore serve as an important source of information for CFD practitioners both in academia and industry.
(iii) RAs who will be engaged in this research programme:
In the proposed research programme, both RAs will learn advanced techniques for CFD simulations and experimental measurements which will improve their analytical and mathematical skills. It is hoped that the experience of presenting their research in the form of peer-reviewed papers and conference presentations will make them well-rounded researchers during the course of this research programme. Moreover, the RAs will need to present their work periodically in progress review meetings and maintain a project website, which will also be beneficial for them in terms of developing project management and presentation skills. These will also help them in developing a range of transferable skills such as communication, teamwork and project management. This, in turn, will give an edge to the RAs in current competitive job market.
(iv) Research group at NU and CUED:
The collaboration between NU and CUED is one of the major strengths of this project which will lead to broadening of research capabilities of all the investigators (i.e. both PIs and CI). Moreover it is expected that this project will give rise to open questions which form the basis of further investigations by the investigators, and the usefulness of the present project will be exploited to attract industrial and research grant funding for its future follow-ups. It is likely that the understanding gained from this project will subsequently be applied to engineering combustion applications, possibly through the Knowledge Transfer Partnership (KTP) scheme in collaboration with industry in future, which will also ensure effective assimilation of this project's outcome in the relevant industrial sectors.
(i) Development of fundamental understanding and modelling of turbulent droplet-laden MILD combustion:
The research outcomes will be disseminated through participation in international conferences (e.g. Int. Combust. Symp., Eur. Combust. Meeting, Numer. Combust. Conf. etc.) and publication in reputed scientific journals (e.g. Combust. Flame, Phys. Fluids, Combust. Sci. Technol., Combust. Theor. Modell. etc.). Moreover, the models developed during the course of this project will enhance the knowledge-base of turbulent reacting flows and predictive capability of engineering simulations, which in turn will play a key role in the design-cycle of next generation energy-efficient and environment friendly combustors. The DNS and LES databases resulting from the proposed research programme will be made available to other interested researchers upon request. The Research Associates (RA) will manage a website for data-exchange and documentation, and important results will be made available for public download. A workshop on MILD combustion will be organised at the conclusion of the project to maximise the chances of technical dissemination, and to attract the attention of relevant industrial sectors.
(ii) IC-engine and gas turbine manufacturers:
Improving the predictive abilities of MILD combustion of droplet-laden mixtures will be of great benefit to these industries for the development of new generation energy-efficient and environment friendly combustors. Industrial colleagues will be invited to attend half-yearly progress meetings and the planned workshop so that they remain aware of the development of the proposed research programme and their feedback will be taken on board during the course of the proposed research programme. A website will be maintained throughout the proposed work with information on data-exchange and documentation, and specific results will be made available for public download along with the latest findings in open literature. It will therefore serve as an important source of information for CFD practitioners both in academia and industry.
(iii) RAs who will be engaged in this research programme:
In the proposed research programme, both RAs will learn advanced techniques for CFD simulations and experimental measurements which will improve their analytical and mathematical skills. It is hoped that the experience of presenting their research in the form of peer-reviewed papers and conference presentations will make them well-rounded researchers during the course of this research programme. Moreover, the RAs will need to present their work periodically in progress review meetings and maintain a project website, which will also be beneficial for them in terms of developing project management and presentation skills. These will also help them in developing a range of transferable skills such as communication, teamwork and project management. This, in turn, will give an edge to the RAs in current competitive job market.
(iv) Research group at NU and CUED:
The collaboration between NU and CUED is one of the major strengths of this project which will lead to broadening of research capabilities of all the investigators (i.e. both PIs and CI). Moreover it is expected that this project will give rise to open questions which form the basis of further investigations by the investigators, and the usefulness of the present project will be exploited to attract industrial and research grant funding for its future follow-ups. It is likely that the understanding gained from this project will subsequently be applied to engineering combustion applications, possibly through the Knowledge Transfer Partnership (KTP) scheme in collaboration with industry in future, which will also ensure effective assimilation of this project's outcome in the relevant industrial sectors.
People |
ORCID iD |
| Nilanjan Chakraborty (Principal Investigator) |
Publications
Abo-Amsha K
(2023)
Flame Self-interaction and Flow Topology in Turbulent Homogeneous Mixture n-Heptane MILD Combustion
in Flow, Turbulence and Combustion
Abo-Amsha K
(2023)
Surface Density Function and Its Evolution in Homogeneous and Inhomogeneous Mixture n -Heptane MILD Combustion
in Combustion Science and Technology
Awad H
(2023)
A Priori Direct Numerical Simulation Assessment of MILD Combustion Modelling in the Context of Reynolds Averaged Navier-Stokes Simulations
in Flow, Turbulence and Combustion
| Description | A small reduction in NOx emission per kilo-watt of generated power will have a significant reduction in environmental impact of combustion used for power generation. The MILD (Moderate or Intense Low-Oxygen Dilution) combustion technique offers an opportunity to drastically reduce emissions while improving thermal efficiency of furnaces and boilers. In gas turbines, though overall fuel-air mixture is fuel-lean and MILD combustion is not directly applicable, fuel-rich regions in the primary zone of the combustor exhibit localised MILD regimes, particularly for liquid fuel operation How-ever, the physical and chemical intricacies of this novel technique are not well understood and thus identifying key control parameters for using this technique for power generation and industrial processes over wide range of conditions is challenging. This project aims to provide a step change in physical understanding and modelling of this combustion technique and to identify key control parameters. The aim is to investigate MILD combustion of high calorific value gaseous and liquid fuels for practical application using Direct Numerical Simulations (DNS) , with high-fidelity mathematical description for physical and chemical processes involved. The droplets of liquid fuel spray will be tracked using the Lagrangian approach while the gas phase is treated using the Eulerian approach for the simulations. The effects of droplet diameter, equivalence ratio (both for gaseous and liquid fuels), extent of dilution by combustion products, volatility (by considering different fuels), turbulence intensity and its length scale on the burning rate, flame structure (in terms of chemical reaction pathways analysis and flame and flow topologies) and pollutants formation will be analysed based on a judicious parametric analysis based on three-dimensional detailed chemistry DNS data. In this project, the fundamental physical understanding extracted from DNS data will be utilised to develop high-fidelity models for engineering Computational Fluid Dynamics (CFD)-based simulations to identify key control parameters using LES after validating these models against the available experimental results. This project will provide (1) a robust modelling framework for MILD combustion technique, which would be a cost-effective reliable tool for designing energy-efficient and clean gas turbines and industrial furnaces and (2) the key control parameters identified can help to design retro-fit "greener" combustion systems. The DNS code is currently functional and production level simulations are currently under way. We are in the process of obtaining fundamental physical insights into the MILD combustion process which will be used for the development of high-fidelity models. |
| Exploitation Route | (i) Development of fundamental understanding and modelling of turbulent droplet-laden MILD combustion: The research outcomes will be disseminated through participation in international conferences (e.g. Int. Combust. Symp., Eur. Combust. Meeting, Numer. Combust. Conf. etc.) and publication in reputed scientific journals (e.g. Combust. Flame, Phys. Fluids, Combust. Sci. Technol., Combust. Theor. Modell. etc.). Moreover, the models developed during the course of this project will enhance the knowledge-base of turbulent reacting flows and predictive capability of engineering simulations, which in turn will play a key role in the design-cycle of next generation energy-efficient and environment friendly combustors. The DNS and LES databases resulting from the proposed research programme will be made available to other interested researchers upon request. The Research Associates (RA) will manage a website for data-exchange and documentation, and important results will be made available for public download. A workshop on MILD combustion will be organised at the conclusion of the project to maximise the chances of technical dissemination, and to attract the attention of relevant industrial sectors. (ii) IC-engine and gas turbine manufacturers: Improving the predictive abilities of MILD combustion of droplet-laden mixtures will be of great benefit to these industries for the development of new generation energy-efficient and environment friendly combustors. Industrial colleagues will be invited to attend half-yearly progress meetings and the planned workshop so that they remain aware of the development of the proposed research programme and their feedback will be taken on board during the course of the proposed research programme. A website will be maintained throughout the proposed work with information on data-exchange and documentation, and specific results will be made available for public download along with the latest findings in open literature. It will therefore serve as an important source of information for CFD practitioners both in academia and industry. (iii) RAs who will be engaged in this research programme: In the proposed research programme, both RAs will learn advanced techniques for CFD simulations and experimental measurements which will improve their analytical and mathematical skills. It is hoped that the experience of presenting their research in the form of peer-reviewed papers and conference presentations will make them well-rounded researchers during the course of this research programme. Moreover, the RAs will need to present their work periodically in progress review meetings and maintain a project website, which will also be beneficial for them in terms of developing project management and presentation skills. These will also help them in developing a range of transferable skills such as communication, teamwork and project management. This, in turn, will give an edge to the RAs in current competitive job market. (iv) Research group: The collaboration between Newcastle University and Cambridge University is one of the major strengths of this project which will lead to broadening of research capabilities of all the investigators (i.e. both PIs). Moreover it is expected that this project will give rise to open questions which form the basis of further investigations by the investigators, and the usefulness of the present project will be exploited to attract industrial and research grant funding for its future follow-ups. It is likely that the understanding gained from this project will subsequently be applied to engineering combustion applications, possibly through the Knowledge Transfer Partnership (KTP) scheme in collaboration with industry in future, which will also ensure effective assimilation of this project's outcome in the relevant industrial sectors. |
| Sectors | Aerospace, Defence and Marine,Energy,Environment |
| Description | Impact through communication and engagement of beneficiaries: The design-cycle of modern gas turbine and industrial furnaces depends heavily on the accurate predictive capability of engineering Computational Fluid Dynamics (CFD) calculations. The fundamental physical insight and the high-fidelity methodology for analysing turbulent MILD combustion of liquid fuels, which will be developed in this project, will have maximum benefit for the manufacturers of new generation gas turbines and industrial furnaces, who are engaged in developing new low-pollution and high-efficiency combustion devices. In the UK, EDF and Renuda, are interested in the outcome of this work (support letters attached), though the benefits are not limited to the UK (e.g. see the support letter of GE) as important findings will be disseminated through peer-reviewed journals and international conference publications. Furthermore, the participating institutions (CUED and NU) and will obtain new tools for the analysis of turbulent reacting flows, helping the PIs to attract industrial funding. Finally, the CFD software community, who use state-of-the-art combustion models extensively, will also be interested in this work. In order to maximise the impact of the project, the PIs and RAs will work actively to publicise the results by attending reputed international conferences (e.g. International Combustion Symposium, European Combustion Meeting, Numerical Combustion Conference) and important UK combustion meetings organised by the British Section of Combustion Institute (BS-CI), UK Consortium on Turbulent Reacting Flows (UKCTRF), Combustion Science and Technology Special Interests Group (SIG) of the UK-Fluids Network and Institute of Physics. Some funding for this purpose has been requested in the Justification of Resources. For a quick knowledge dissemination into relevant industries, industrial colleagues will be invited to attend the progress review meetings and their feedback will be sought for subsequent steps of the project. Moreover, interested industrial colleagues will be invited to attend the workshop planned at the end of the project so that the capability of the newly developed methodology can be demonstrated, which will encourage its use amongst industrial partners. Given the long-term nature of the design-cycle of gas turbines and industrial furnaces, and the time required to build up enough confidence in the community, it is likely that the impact in terms of new product and wealth creation will be felt in a time scale of 10-20 years after the completion of the project. The technological advancements of this project will also help in designing energy efficient and environment friendly combustors, which will also bring long-term benefits (in a time scale of 10-20 years) for society. The RAs will maintain an interactive project website in which the existing knowledge on turbulent MILD combustion will be summarised and web-links will be provided for easy access to relevant previous publications by the PIs, and the conference and journal publications resulting from this project. The website will have information on data-exchange and documentation, and specific results will be made available for public download along with the latest findings in the open literature. This website will be particularly important for commercial CFD companies who will have cutting-edge information on the subject, and can implement the models in industrial CFD codes. The impact of this project in terms of proving a competent CFD software tool is likely to be felt in about 5-10 years' time after the completion of the project. The PIs have existing collaborations with several international research laboratories (e.g. Kyoto University, Kyushu University, Tokyo Institute of Technology, Sandia National Laboratory, University of Sydney, Bergen University, ETH-Zurich, University of Duisburg, University of Bundeswehr Munich, etc.) and the results of this project will be publicised during mutual research visits. The simulation database resulting from the project will also be made available to other interested researchers upon request. A one-day workshop on the physics of turbulent MILD combustion and its model-ling will be organised at CUED. This workshop will be the backbone for making the desired impact and publicising the scientific and technical achievements in this project, and will thus substantially increase the chance of short-term im-pact and provide a platform for long-term benefits for the economy and the society as a whole. Impact through collaboration : The collaboration between CUED and NU on complementary aspects and skill sets is one of the major strengths of this project. On completion of this project, the PIs will have DNS and LES databases which can be used for further analyses. This will lead to broadening of research capabilities of the PIs. Moreover, academic and industrial contacts will be shared by the PIs during the project period, which will be beneficial to disseminate research outcomes in both academia and industry. The collaboration with research groups will add new dimensions to the academic developments of the RAs who will be employed in this project. They will also have opportunities to interact with experts from both academia and industrial sectors during the proposed workshop, WS1, which will immensely help their academic development, and provide a range of transferable skills such as communication, teamwork and project management. This, in turn, will give an edge to the RAs in the current competitive job market. Furthermore, the RAs need to present their work periodically in progress review meetings, annual meetings of UKCTRF, Combustion and Science and Technology SIG meetings and maintain a website, which will be beneficial in developing their project management and presentation skills. The research outcomes will be disseminated in leading international conferences (e.g. Int. Symp. of Comb., Eur. Comb. Meeting, Mediterranean Comb. Symp. etc) in addition to the aforementioned meetings, and in the planned workshop at the end of this project, which is expected to initiate valuable discussions with other UK and international colleagues, and open up possibilities for further collaboration. The workshop will provide a unique opportunity to the investigators to expand their collaborative network. During this workshop, the investigators will explore avenues for common interest with the invited speakers, develop new ideas, and initiate plans for new collaborative research ventures. The close interaction with this research group will open-up possibilities for further future collaboration. Impact by exploitation and application of project outcomes The project outcomes will be disseminated through participation in international academic conferences (e.g. Int. Comb. Symp., Eur. Comb. Meeting) and publication in reputed scientific journals (e.g. Comb. Flame, Phys. Fluids, Comb. Theory and Modelling etc.). The results will also be presented at meetings of ASME Gas Turbine meetings to disseminate the main findings within the gas turbine sector. A one-day workshop will be organised in CUED at the end of this project to popularise project outcomes as widely as possible and to make them directly available to the UK and international combustion community. This proposed workshop will be different from the usual British Section-Combustion Institute and Institute of Physics meetings because it will focus only on turbulent MILD combustion and its modelling. This workshop will help in publicising the project outcomes, which, in turn, will help in a relatively quick assimilation of newly developed models in industrial CFD calculation for designing new generation high efficiency, low pollution gas turbines and industrial furnaces. Much of the benefit of the modelling activity will not only be limited to turbulent MILD combustion, but also contribute to the modelling of turbulent reacting flows in general. This project will provide information on the validity of Partially Stirred Reactors (PaSR), flamelets (e.g. Flame Surface Density and Scalar Dissipation Rate), Conditional Moment Closure (CMC) and Probability Density Function (PDF) modelling methodologies in the case of MILD combustion in droplet-laden mixtures. The high fidelity and robust models to be developed in this project will lead to improved prediction from CFD simulations, which can help in the economical design of gas turbines and industrial furnaces for better efficiency and environment friendliness. This suggests that the findings of this research endeavour will be of particular interest to industrial process heating and gas turbine sectors of the industry (e.g. EDF,GE and Renuda, to name a few). This is especially important as the world-wide demand for natural oil would increase by 45% by 2030 and thus improved physical understanding and modelling methodology for turbulent MILD combustion are not only timely but also essential for addressing the challenges of energy-efficiency and pollution control. Given the fundamental nature of this project, the proposed investigation will certainly give rise to some open questions, which will then form the basis for further investigations by the applicants. The useful outcomes of this project are expected to attract funding from industries and other sources for future follow-ups and it is likely that the fundamental understanding gained from this project will subsequently be applied to engineering combustion applications through the Knowledge Transfer Partnership (KTP) scheme in collaboration with industry in a 2-10 years' time scale. This will then ensure effective assimilation of this project's outcome in the relevant industrial sectors. The efforts of PIs in this respect are also marked as milestone M3 in the attached Work-plan. The impact due to dissemination of project outcomes is expected to be realised in about 2-5 years' time, as it will take sustained effort after the completion of the project to build up enough confidence within the research community in the methodology proposed in order to make it a viable tool for designing new generation gas turbines and industrial furnaces. Impact through capability development and knowledge exchange: The proposed project is based on the collaboration between two research groups, which will ensure an extensive knowledge exchange between PIs and the RAs working in this project. This project will not only provide opportunities to broaden the investigators' research horizon but will also be highly valuable for the RAs for their academic and career development. The RAs will receive extensive training on a variety of topics such as advanced high-performance computing techniques, fluid turbulence, chemical kinetics and combustion model development. They will also learn advanced techniques for high performance computing, which will improve their analytical and mathematical skills, and will also practise teamwork and collaboration. The regular presentations in various meetings (e.g. annual progress meetings, annual meetings of UKCTRF, Combustion and Science and Technology SIG meetings), managing the project website and close interaction between several research groups will also improve the presentation and communication skills of the RAs. This project lays substantial emphasis on transferable skills of the RAs and increases the chances of their employability. As a result, this project will give rise to the development of two well-rounded researchers who will eventually carry the expertise gained during this project period in their future roles irrespective of academic or industrial nature. It is noted earlier that project outcomes will be presented in front of various academic and industrial colleagues at different stages of the project to disseminate its findings to the maximum extent, which will ensure knowledge ex-change from participating institutions to interested parties in the industrial sector. Moreover, the expertise generated in this project will also be helpful in expanding PIs' research groups in their respective institutions. The impact through capability development will be felt immediately through the RAs (in a timescale of 2-4 years), and the expertise developed in the project is likely to bring long term benefits to the investigators and their respective institutions in terms of future funding and expansion of the respective research groups. |
| First Year Of Impact | 2020 |
| Sector | Aerospace, Defence and Marine,Energy,Environment |
| Impact Types | Societal |