Low NOx / low sOot injection system design for sPinning combuStion technology

ended

Safran Helicopter Engines has recently developed and patented a new spinning combustion technology (SCT). This innovative technology improves ignition and blow-off capabilities and enables combustor weight reduction, without compromising turbine nor combustor lifetime. To further promote this highly promising technology, the next step is to assess SCT performances in terms of NOx and soot emissions. Indeed, new aeronautical technologies entering the market today must comply with international regulations and answer the public environmental concern about global warming and human health. To assist Safran in this development phase, the LOOPS project aims to design, manufacture, test and model an advanced low-NOx and low soot/particles injection system for SCT. The technology is based on the multi-point injection concept, which has already demonstrated very good low-NOx capabilities. The challenge is to guarantee low soot emission as well, which may be detrimental to other pollutant reduction. Two injectors will be designed and evaluated in a systematic way for both NOx and soot emission using combined measurements and numerical simulation. On the experimental side, the most advanced experimental diagnostics will be used, providing in particular and for the first time a complete and detailed characterization of the soot particles with their concentration and size distribution. On the numerical side, a significant contribution of LOOPS will be the assessment and application of accurate models for NOx and soot production in real helicopter engines. The confrontation of measurements and simulation results will allow to evaluate the accuracy of the numerical approach and to better understand the underlying mechanisms of pollutant emissions. In addition to a new low-emission injector systems for SCT, outputs of the project will be guiding rules, as well as an engineering numerical tool for low-emission SCT, allowing to find the best compromise between competing phenomena.