SAMULET_Project_2_Combustion Systems for Low Environmental Impact

Future sales of aero gas turbine products are dependent on the ability to deliver propulsion systems that are competitive and meet current and anticipated environmental legislation. Customers are increasingly prioritising emissions performance in their selection process. This means new combustor designs must deliver high fuel efficiency and low emissions of oxides of nitrogen (NOx), unburnt combustion products, and particulates. The most powerful route to improving fuel efficiency is via higher pressure ratios, higher bypass ratios, and higher core temperature ratios, all resulting in higher combustion temperatures. This directly impacts on NOX, so the combustion system has to reduce emissions performance for a given thermodynamic cycle just to maintain current emissions levels. Step changes in NOX emissions technology are thus required. This can be delivered if appropriate lean burn combustion technology for large engines and improved rich burn technology for smaller products can be developed. To achieve this target requires improved knowledge and innovative ideas to be created via fundamental research into: 'quiet' low emissions fuel injectors, new techniques for predicting/managing combustion instability, advanced measurement techniques for kerosene/alternative fuels, improved fuel control systems, better design of combustor cooling systems, and methods for accurate lifing of combustors using novel approaches to manufacturing incorporating the effects of residual stresses.