Study of Interacting Turbulent Flames Using Direct Numerical Simulation and Laser Diagnostics
Lead Research Organisation:
University of Cambridge
Department Name: Engineering
Abstract
Emissions legislation is becoming ever more stringent and the conventional combustion technologies are incapable of meeting the low ppm levels set by the new legislation. Thus, alternative technologies need to be found and the lean burn concepts have the ability to meet the standards but the ignitability and flame stability of lean premixtures need to be understood clearly. However, lean premixed flames are prone to thermo--acoustic instabilities, because of their high sensitivity to even small scale variations in the fluid dynamic and thermo--chemical state of the mixture. It is becoming clear that interacting flames are a dominant mechanism for creating thermo--acoustic oscillations in lean premixed combustion. Premixed combustion is often more difficult to simulate than nonpremixed combustion, because of the propagation of reacting surfaces in premixtures, with the consequence that engineering models for turbulent premixed combustion are significantly less well developed than those for nonpremixed combustion. A major unsolved problem is to provide a satisfactory description of the small scale interactions between reacting surfaces, within a flame brush, which form the major mechanism for limiting the growth of reacting surface area. Because of this fundamental limitation, existing models are not well adapted to describe the large scale flame-flame interactions that give rise to pressure variations and thermo-acoustic instabilities in combustion chambers.In the present work, we propose to investigate the mutual interaction between flames at a fundamental level using direct numerical simulation and laser diagnostics. In the configuration of twin ``V'' flames considered here the interaction process is controlled by the upstream turbulence and yields a sufficiently long interaction time for statistical sampling in experiments. This geometry is akin to burner--to--burner interaction process inthe annular combustor of a gas turbine engine, and the interaction process to be simulated is considered to be a valid representation of behaviour in turbulent flames. The expected outcome from this work is a close understanding of processes occurring during interaction between flames, leading to development of a revised model for premixed turbulent combustion, containing a physically valid description of processes limiting growth of flame surface area, and with a capability to simulate large scale flame-flame interactions.
Publications
Dunstan T
(2013)
The Effects of Non-Unity Lewis Numbers on Turbulent Premixed Flame Interactions in a Twin V-Flame Configuration
in Combustion Science and Technology
Liu Y
(2012)
Spatial correlation of heat release rate and sound emission from turbulent premixed flames
in Combustion and Flame
H. Kolla
Scalar gradients and dissipation rates in strained laminar premixed flames
in 8th Asia-Pacific Conference on Combustion
Dunstan T
(2013)
Scalar dissipation rate modelling for Large Eddy Simulation of turbulent premixed flames
in Proceedings of the Combustion Institute
L.F. Caracciolo
(2012)
Prediction of noise source for an aeroengine combustor
T. D. Dunstan
Phenomenology and modelling of premixed flame interactions using twin turbulent V-flames
in 13th International Conference on Numerical Combustion
T. D. Dunstan
(2014)
Non-reflecting boundary conditions for multi-dimensional turbulent flames
Y. Liu
Modelling of combustion noise spectrum from turbulent premixed flames
in ACOUSTICS
Dunstan T
(2012)
Influence of flame geometry on turbulent premixed flame propagation: a DNS investigation
in Journal of Fluid Mechanics
Dunstan T
(2010)
Geometrical Properties and Turbulent Flame Speed Measurements in Stationary Premixed V-flames Using Direct Numerical Simulation
in Flow, Turbulence and Combustion
T. D. Dunstan
(2011)
Flame surface density measurements in interacting premixed flames using experiment and DNS
in 23rd International Colloquium on the Dynamics of Explosions and Reactive Systems
Dunstan T
(2013)
Flame Interactions in Turbulent Premixed Twin V-Flames
in Combustion Science and Technology
Dunstan T
(2010)
Erratum to: Geometrical Properties and Turbulent Flame Speed Measurements in Stationary Premixed V-flames Using Direct Numerical Simulation
in Flow, Turbulence and Combustion
Minamoto Y
(2011)
Effect of flow-geometry on turbulence-scalar interaction in premixed flames
in Physics of Fluids
Minamoto Y
(2013)
DNS of EGR-type turbulent flame in MILD condition
in Proceedings of the Combustion Institute
Y. Minamoto
(2011)
DNS of EGR-type combustion in MILD condition, paper No. TC-39
in 7th Mediterranean combustion symposium
S. Ruan
(2013)
Computations of turbulent premixed flame response to inlet velocity oscillation
in 24th International Colloquium on the Dynamics of Explosions and Reactive Systems
Gao Y
(2015)
Assessment of Reynolds Averaged Navier-Stokes Modeling of Scalar Dissipation Rate Transport in Turbulent Oblique Premixed Flames
in Combustion Science and Technology
Description | Different types of flame-flame interactions and frequency of their occurrence. These information, specifically the frequency, has be found for the first time. |
Exploitation Route | The knowledge gather can be translated into a mathematical model which can then be implemented in to existing or a new computer code to study sound emissions from flames. |
Sectors | Aerospace Defence and Marine Education Energy Transport |
Description | Yet to be used in relevant industries |
First Year Of Impact | 2014 |
Sector | Aerospace, Defence and Marine,Education,Energy,Transport |
Impact Types | Economic |
Description | Rolls-Royce Plc |
Amount | £115,990 (GBP) |
Funding ID | NMZA/778 |
Organisation | Rolls Royce Group Plc |
Sector | Private |
Country | United Kingdom |
Start | 04/2011 |
End | 12/2012 |
Description | Rolls-Royce Plc |
Amount | £115,990 (GBP) |
Funding ID | NMZA/778 |
Organisation | Rolls Royce Group Plc |
Sector | Private |
Country | United Kingdom |
Start |
Title | DNS of single and double oblique flames |
Description | A collection of numerical data from high fidelity simulations of single and twin "Vee" flames. |
Type Of Material | Database/Collection of data |
Year Produced | 2014 |
Provided To Others? | Yes |
Impact | Improved knowledge and understanding of flame-flame interaction, helping us to build better mathematical models for turbulent lean combustion. |
Title | Models for interacting flames |
Description | A mathematical model to explore the interactions of flamelets |
Type Of Material | Computer model/algorithm |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | None yet |
Description | Research Collaboration with TokyoTech |
Organisation | Tokyo Institute of Technology |
Department | Furui-Lab |
Country | Japan |
Sector | Academic/University |
PI Contribution | Because of the initial collaboration with Tokyo Tech through this project, the PI has been invited to collaborate with TokyoTech on a number of research and educational projects. The PI has been invited to be a co-investigator on two research projects (2010-13, 2011-15) on turbulent combustion with a combined total value of about £2.7M, awarded to Tokyo Tech by JSPS and MEXT. The PI has been invited to be an international co-operative partner in their 6 year educational programme with a value of about £25M awarded to Tokyo Tech by MEXT. The initial interaction through this project has evolved into a strong and successful collaboration. |
Collaborator Contribution | The partner allowed us to use their numerical simulation data to get insights required for model development in this project |
Impact | the papers resulted from this collaboration are listed in the publication list. |
Start Year | 2006 |