ID 410

A study of ECN Spray A using An Improved Stochastic Blob (VSB2) Spray Model

 

Abstract:

Accurate prediction of spray formation is crucial when modeling spray combustion. In this work an existing Eulerian-Lagrangian spray model, VSB2 has been extended to account for secondary break-up in a more accurate way, by creating child blobs from the stripped of mass for each blob undergoing break up. The new break-up approach was compared with the old approach for the ECN spray A baseline case at 900 K, where the impact of the new method did not show much impact. When the ambient temperature was lowered to 700 K, the new method showed a much more pronounced effect on the liquid penetration. It was concluded that with the new break up treatment, smaller blobs from the stripped off mass is created downstream of the spray, causing the liquid to evaporate faster as the smaller blobs with less momentum get more easliy dispersed into the bulk, where more energy is available for evaporation. A reduction in turbulence was also observed as a result of the lower velocity gradients created by the lower momentum contained in the smaller blobs.