ID 228

Study of Energy Cascade in Spray Near-Field

 

Abstract:

A growing interest has been observed in the scientific community about the study of the dense region in sprays Near-Field. The limited understanding on the physical phenomena involved in this region is definitely limiting the capability of obtaining usable and understandable data for practical design purpose. Furthermore, the dense region is particularly challenging to access optically, as the equipment needed for experiments is extremely expensive and the optical setup results increasingly difficult to calibrate as the characteristic length of the phenomena decreases. Among the years, only few Direct Numerical Simulations have been performed on the spray’s Near Field, mainly aiming to shed light on the atomization process. On the other hand, very few insights have been provided on the behavior of the turbulence field in this region, where the distribution of energy among the motions scales is arguably one of the most important causes of the atomization process. In this context, the present work proposes a methodology to study the energy cascade occurring in the Near-Field (at x/D=25). The analysis has been done at a moderately high Reynolds number (Re=5050) for a dodecane fluid injected in calm and quiescent air. As it is well assessed the influence of the turbulence generated within the nozzle on the spray early atomization, a synthetic turbulence boundary condition has been used in the spray modelling. Among the various approaches proposed in literature, the model of Klein et al. have been used, as it has demonstrated its capability for sprays DNS in past activities.