COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring. |

University of Cambridge > Talks.cam > Fluid Mechanics (DAMTP) > Asymptotic theory for acoustic instability of premixed combustion

## Asymptotic theory for acoustic instability of premixed combustionAdd to your list(s) Download to your calendar using vCal - Professor Xuesong Wu, Mathematics, Imperial College London
- Friday 06 December 2013, 16:00-17:00
- MR2, Centre for Mathematical Sciences, Wilberforce Road, Cambridge.
If you have a question about this talk, please contact Dr C. P. Caulfield. Acoustic instability of premixed combustion refers to large-scale self-sustained pressure fluctuations in a combustion chamber. It is a typical multi-physics, multi-scale problem in the sense that it arises due to complex interactions among chemical reaction, heat and mass transport, hydrodynamics and acoustics, which take place on distinctively different scales. Such disparity of scales presents a formidable challenge for direction numerical simulations, but can be exploited mathematically to derive simplified systems. Asymptotic techniques, such as matched asymptotic expansion, can be used to analyse the small-scale inner structure of the flame, thereby characterizing the mutual interaction between the flame and the ambient flow motion. In the so-called flamelet regime, where the length scale of the flow motion is much greater than the flame thickness, this leads to the classical hydrodynamic theory of premixed combustion. However, the theory assumes that the enthalpy (temperature and the mass fraction of the fuel) in the oncoming mixture are steady and homogeneous, and the spontaneous sound of the flame is not accounted for explicitly. We extends the formulation by allowing for enthalpy fluctuations, and show that unsteady combustion necessarily emits spontaneous sound, which acts simultaneously on the flame. The resulting general theory for the flame-flow-acoustic interactions is applied to simple cases to provide insights into fundamental mechanisms of acoustic instability of premixed combustion. This talk is part of the Fluid Mechanics (DAMTP) series. ## This talk is included in these lists:- All CMS events
- All Talks (aka the CURE list)
- CMS Events
- CamBridgeSens
- Combined External Astrophysics Talks DAMTP
- Cosmology, Astrophysics and General Relativity
- DAMTP Fluids Talks
- DAMTP info aggregator
- Fluid Mechanics (DAMTP)
- Life Science Interface Seminars
- MR2, Centre for Mathematical Sciences, Wilberforce Road, Cambridge
- SJC Regular Seminars
- School of Physical Sciences
- Talks related to atmosphere and ocean dynamics and climate science
- UCCRI
Note that ex-directory lists are not shown. |
## Other listsStudent Community Action A Year at the Synapse: where Pre meets Post Visiting Scholar Seminars## Other talksChains and Invisible Threads: Marx on Republican Liberty and Domination Nonlinear elasticity and image processing Title TBC Realist Reviews of health interventions – dealing with complexity and context Convex Optimization Self-Assembled Nanomaterials for 3D Bioprinting and Drug Delivery Applications |