Premixed Combustion Flame Instability Characteristics (PREFIC)
Lead Research Organisation:
University of Birmingham
Department Name: Mechanical Engineering
Abstract
Cellular instability and self-acceleration of premixed flames are commonly observed in fuel combustion, due to the thermal-diffusive and hydrodynamic instability. Cellar instability significantly influences the flame structure and speed, and the resultant self-acceleration has been widely observed in spherical flame studies, with high influences on the turbulent burning velocity of various combustion systems and causing higher fire and explosion hazards. Mapping the regimes of cellular instability and self-acceleration could help improve combustion modelling which is widely used in design of combustion systems and investigation of fire and explosion hazards.
The project is divided into two main work packages, in which the research is moving from basic dada acquirement to the cause of instability and in the end of the consequence of self-acceleration.
The flame cellular structure will be mathematically characterised and quantified by the microscopic photography and image processing technique rather than traditionally by measuring burning velocity through calculation of flame size or pressure history.
A newly defined Cellularity Factor is introduced to represent the flame cellular structure characteristics, and the variation regularity of flame front cells is firstly calculated and analysed by measuring the cellular structure parameters, which are the primary parameters to quantitatively determine the critical point of the fully developed cellular flame and to describe the self-acceleration. Present work will develop a new burning velocity model for flame acceleration.
Improved correlations are proposed, incorporating transient and multidimensional effects, as finite rate chemistry, which are crucial for the predictive engineering model developments.
The project is divided into two main work packages, in which the research is moving from basic dada acquirement to the cause of instability and in the end of the consequence of self-acceleration.
The flame cellular structure will be mathematically characterised and quantified by the microscopic photography and image processing technique rather than traditionally by measuring burning velocity through calculation of flame size or pressure history.
A newly defined Cellularity Factor is introduced to represent the flame cellular structure characteristics, and the variation regularity of flame front cells is firstly calculated and analysed by measuring the cellular structure parameters, which are the primary parameters to quantitatively determine the critical point of the fully developed cellular flame and to describe the self-acceleration. Present work will develop a new burning velocity model for flame acceleration.
Improved correlations are proposed, incorporating transient and multidimensional effects, as finite rate chemistry, which are crucial for the predictive engineering model developments.
Publications
Ahmed P
(2024)
Development of a multiple laser-sheet imaging technique for the analysis of three-dimensional turbulent explosion flame structures
in Physics of Fluids
Al-Khafaji M
(2025)
The measurement of turbulent burning velocities of methane-hydrogen-air mixtures at elevated pressures in a spherical vessel
in Combustion and Flame
Morsy M
(2022)
The instability of laminar methane/hydrogen/air flames: Correlation between small and large-scale explosions
in International Journal of Hydrogen Energy
Xie Y
(2024)
Flame wrinkling and self-disturbance in cellularly unstable hydrogen-air laminar flames
in Combustion and Flame
Xie Y
(2025)
Three-dimensional dynamics of unstable lean premixed hydrogen-air flames: Intrinsic instabilities and morphological characteristics
in Combustion and Flame
Xie Y
(2023)
Laminar burning characteristics of coal-based naphtha
in Combustion and Flame
| Description | several key publications have been made |
| Exploitation Route | Results in the publications and key technologies in software developed will be used by industrial partners and readers |
| Sectors | Aerospace Defence and Marine Digital/Communication/Information Technologies (including Software) Energy Transport |
| URL | https://www.birmingham.ac.uk/research/activity/mechanical-engineering/case-centre |
| Description | Solutions for a new generation of fuel additives |
| Amount | £20,000 (GBP) |
| Organisation | Shell Centre |
| Sector | Private |
| Country | United Kingdom |
| Start | 12/2022 |
| End | 12/2023 |
| Description | Utilization of hydrogen-containing fuel |
| Amount | £48,000 (GBP) |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 11/2022 |
| End | 11/2024 |
| Description | |
| Type Of Material | Improvements to research infrastructure |
| Provided To Others? | No |
| Title | Deep learning pre-training model for surface cell information extraction of spherical premixed flames |
| Description | The Cellpose 2.0, driven by deep learning, is innovatively introduced from the biology field to train the cell segmentation model in the combustion field. After labeling and training cells of different shapes and sizes, an efficient and accurate model suitable for cell feature extraction was finally obtained to identify and quantify various cell characteristics, such as number, size, and distribution. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | The cell segmentation model obtained in this work can be further used to train other spherical flames under various experimental conditions, helping to develop fuel combustion and explosion models. |
| URL | http://tinyurl.com/yt2ysvah |
| Description | Collaboration with Aston University |
| Organisation | Aston University |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Presented at the early career research day |
| Collaborator Contribution | Workshops, networking and job opportunities |
| Impact | PhD is now employed as a business engagement officer at Aston University. |
| Start Year | 2018 |
| Description | Fuel combustion technology development |
| Organisation | Shell International Petroleum |
| Department | Shell UK Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Experiment, modeling, research manpower, and other project cost |
| Collaborator Contribution | Shell has supported our research in combustion since 2010. The support includes supplying fuel, manpower, and management. The support agreed to this project by Shell is 20,000GBP |
| Impact | joint publications |
| Start Year | 2010 |
| Description | proposal with Hainan University to explore a programme with support of Hainan Province China for new bio-fuels (visit to take place on 4/4/2023) |
| Organisation | Hainan University |
| Country | China |
| Sector | Academic/University |
| PI Contribution | UoB proposes a new production method of making biofuels using TCR technology developed in the EPSRC project |
| Collaborator Contribution | Hainan University organises a visit from UoB |
| Impact | Our discussions are based on the information in the website above |
| Start Year | 2023 |
| Title | Image Processing Code |
| Description | This in-house code can be used to calculate the surface area of a spherical flame. |
| Type Of Technology | Webtool/Application |
| Year Produced | 2023 |
| Impact | The calculated surface area can be employed to develop the combustion model for the spherical flame, such as hydrogen, ethane, and propane, etc. |
| Title | Quantitative Three-Dimensional Reconstruction Method of Cellular Flame Area for Spherical Premixed Flames |
| Description | A concept of peak height h on the flame profile was proposed to characterize the fluctuation degree of flame profile. A new flame equivalent radius r_u was defined by the average value of valid distance from flame centroid to flame profile pixel by pixel. Based on the comparison of cell equivalent radius r and average peak height h ¯, an innovative 3D reconstruction concept was proposed for the quantitative characterization of flame area. |
| Type Of Technology | New/Improved Technique/Technology |
| Year Produced | 2024 |
| Impact | This method aims to accurately reconstruct the surface area of a three-dimensional spherical premixed flame. The results can provide data support for the construction of combustion models in the field of premixed combustion. |
| Description | Hydrogen Integration for Accelerated Energy Transitions (HI-ACT) |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | Experts from industry and schools from the National Hydrogen Research Hub participated in the event, which led to a lively discussion on the utilization of hydrogen energy, and it was evident that the interest in related disciplines has increased. |
| Year(s) Of Engagement Activity | 2022 |
| Description | UnICE3G Meeting: Future Propulsion Systems-Combustion Characteristics of Hydrogen, Propane and Methane Gases in a Boosted Featureless Port-Injection SI Engine |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | Founded in 1968, UnICE3G, the Universities' Internal Combustion Engines, Electrification and Energy Group, is an active group of researchers that looks to internally circulate research and development. Comprising of roughly 100 members in a 50-50 split between academia and industry, the group encourages collaboration between UK thermal propulsion, electrification, and energy research groups as well as organisations such as the APC and EPSRC. We participated in this famous academic conference held in Bath on December 7, 2023. This conference gathered the latest developments in the field of internal combustion engines, such as vehicle electrification, energy, fuels, and zero-impact emissions, with a special focus on the research progress of zero-carbon fuels like ammonia and hydrogen. The conference provided us all with an excellent opportunity to consider the direction and prospects of internal combustion engines in a carbon-neutral society from a broad and comprehensive perspective. |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://www.unice3g.org.uk/7-december-2023-iaaps-bath |
| Description | UnICEG Meeting |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | We attended a reputational academic conference at Oxford University. This session collects the recent advances in the development of ICEs (e.g. vehicle electrification, energy, fuels, and zero impact emissions). Based on both a broad and comprehensive perspective, the meeting provided a good opportunity for all of us to consider the future realities of automobiles, energy, and society in a carbon-neutral society. |
| Year(s) Of Engagement Activity | 2022 |