MoST: Multi-scale modification of swirling combustion for optimized gas turbines (10425)

Gas turbine combustion is the most important energy conversion method in the world today. Using gas turbines, large scale, low emission energy production is possible. Nitrogen oxide emissions are one of the most important technology drivers for combustion systems today. For land based engines, low NOx emissions can be achieved by very lean premixed combustion (dry low NOx). Flame stabilization is based on high swirl combustors. A new technology is based on low swirl combustion in which NOx levels can be even lower. In addition to this, in recent years it was found that the mixing efficiency of turbulent flows could be strongly increased by the supply of the 'correct' perturbations. This phenomenon is referred to as "resonant mixing"; it was shown that temporal and spatial perturbations at suitable scales increase mixing by 50 % or more at the same power input. The idea of the present research is to optimize low swirl burners by adding resonant mixing perturbations. Here the turbulence length scale, intensity and the amount of swirl are key parameters. The Ph.D. student will conduct numerical simulation by means of DNS and LES, with appropriately reduced chemistry to find optimal conditions for implementation in future gas turbine technology. The project is conducted in cooperation with experimental research at Twente University.