To reduce the CO2 footprint of aviation, sustainable aviation fuels (SAFs) are regarded as an ideal mid-term solution. These fuels are produced from non-fossil fuel feedstock including waste oil and fats, green and municipal waste and non-food crops. Therefore, they reduce the overall CO2 emissions (per fuel lifecycle) by 80%. The fuel is then injected as a fine spray of liquid droplets which is combusted in aircraft jet engines to produce power.

While these fuels are designed to possess similar chemical properties to that of conventional jet fuels (aviation kerosense), their spray characteristics and the response of sprays to acoustic perturbations is unknown. The CoSAF project aims to investigate the acoustic response of SAF fuel sprays and spray flames and understand the differences to jet A1 fuels. The motivation for this project is to get insight into combustion instability, a practical problem in aircraft jet engines, which arises due to flame-acoustic resonances and leads to reduced engine performance and noise.

Experimental and analytical techniques will be used to investigate the acoustic response of SAF sprays and spray flames. The experiments performed by project partners at BME (Hungary) will be utilized to formulate analytic models to investigate the flame dynamics.