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Projects: Projects for Investigator
Reference Number EP/I017240/1
Title Tackling Combustion Instability in Low-Emission Energy Systems: Mathematical Modelling, Numerical Simulations and Control Algorithms
Status Completed
Energy Categories Energy Efficiency(Industry) 10%;
Fossil Fuels: Oil Gas and Coal(Oil and Gas, Oil and gas combustion) 90%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Applied Mathematics) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Dr X Wu
No email address given
Imperial College London
Award Type Standard
Funding Source EPSRC
Start Date 01 September 2011
End Date 31 August 2014
Duration 36 months
Total Grant Value £392,397
Industrial Sectors Energy
Region London
Programme Energy Research Capacity, Mathematical Sciences
Investigators Principal Investigator Dr X Wu , Mathematics, Imperial College London (99.999%)
  Other Investigator Dr AS Morgans , Aeronautics, Imperial College London (0.001%)
  Industrial Collaborator Project Contact , Siemens Industrial Turbomachinery (0.000%)
Project Contact , Rolls-Royce PLC (0.000%)
Web Site
Objectives Linked to grant EP/I016570/1
Abstract Combustion instability is characterized by large-amplitude pressure fluctuations in combustion chambers, and it presents a major challenge for the designer of high-performance, low-emission energy systems such as gas turbines. The instability arises due to complex interactions among acoustics, heat release and transport, and hydrodynamics, which occur over a huge span of time/length scales.In thepast, various aspects of the interaction were modelled in isolation, and often on an empirical basis. Advanced mathematical techniques, matched asymptotic expansion technique and multiple-scale methods, provide a means to tackle this multi-physical phenomenon in a self-consistent and systematical manner. By using this approach, a first-principle flame-acoustic interaction theory, valid in the so-called corrugated flamelet regime, has been derived recently. The reduced system in the theory ratains the key mechanisms of combustions instability but is much more tractable computationally. In the present proposed project, the flame-acoustic interaction theory will be extended first to account for the influence of a general externally imposed perturbation. A more general asymptotic theory willbe formulated in the so-called thin-reaction-zone regime. Numerical algorithms to solve the asymptotically reduced systems will be developed. The asymptotic theories and numerical methods provide, in principle, an efficient tool for predicting the onset of combustion instability. The fidelity of this approach will be assessed by accurate direct numerical simulations (DNS). It will be applied tothe situations pertaining to important experiments in order to predict a number of remarkable phenomena, such as self-sustained oscillations, flame stabilization by pressure oscillations, parametric instability induced by pressure and/or enthalpy fluctuations and onset of chaotic flames. The theoretical models will be employed to develop effective active control of combustion instability by modulating fuel rate, and the effectiveness and robustness of the controllers designed will be tested by simulations using the asymptotic models as well as the fundamental equations for reacting flows
Publications (none)
Final Report (none)
Added to Database 15/12/10