A major motivation for research in combustion science and technology is to reduce emissions from power plants, large scale industrial furnaces, automobiles, aircrafts, etc. Development of low emission gas turbines has placed a great demand for novel methodologies for emission control, without compromising power production.
Lean premixed combustion systems emerged as a viable solution to the problem, and has been successfully implemented in stationery gas turbine based energy production units, meeting the same energy demands and reducing emissions to single digit ppm levels. Premixed combustion systems offer better control over the flame temperature, which is directly linked to and CO emissions.
However, premixed combustion systems are susceptible to combustion instabilities, which is the coupling between heat release, pressure and flow acoustics, which can lead to high amplitude pressure oscillations. These oscillations can cause severe damage to the combustor hardware and flame flashback.
Successful prediction of thermo-acoustic instabilities is challenging due to the complex flow phenomena, unsteady heat release and undefined acoustic boundaries.
We built a fully premixed experimental swirl stabilized combustion system at the Fine rocket propulsion center to analyze the effect of injecting dilution gases in specific regions of the combustor as a way to reduce combustion instabilities.
