An investigation of characteristics of airblast atomization using 3D DNS for altitude relight conditions

International audienceThis paper presents results from direct numerical simulations (DNS) of planar pre-filming airblast atomization. The liquid/gas interface has been captured using coupled level set moment of fluid method. This method is a hybrid between moment of fluid and coupled level set volume of fluid methods. The numerical method has been applied to airblast atomization analyzed experimentally by Gepperth et al. (2012, "Ligament and Droplet Characteristics in Prefilming Air-blast Atomization", ICLASS 2012). The operating point investigated in this work correspond to aircraft altitude relight condition. The post-processing of the DNS data is performed consistently with that for the experimental data. The main mode of breakup observed is torn sheet breakup. A good agreement was found between simulations and experiments for Sauter Mean Diameter and droplet streamwise velocity distribution while satisfactory agreement has been found for the droplet diameter distribution and ligament breakup length