Analysis of Diesel Spray Structure by Using a Hybrid Model of TAB Breakup Model and Vortex Method 2001-01-1240
This study proposes a hybrid model which consists of modified TAB(Taylor Analogy Breakup) model and DVM(Discrete Vortex Method). In this study, the simulation process is divided into three steps. The first step is to analyze the breakup of droplet of injected fuel by using modified TAB model. The second step based on the theory of Siebers' liquid length is analysis of spray evaporation. The liquid length analysis of injected fuel is used for connecting both modified TAB model and DVM. The final step is to reproduce the ambient gas flow and inner vortex flow injected fuel by using DVM. In order to examine the hybrid model, an experiment of a free evaporating fuel spray at early injection stage of in-cylinder like conditions had been executed. The numerical results calculated by using the present hybrid model are compared with the experimental ones. The calculated results on gas jet flow by DVM quantitatively well correspond to the experimental results for the downstream of evaporative spray. It is also confirmed that an ambient gas flow occupies the downstream region flow in diesel spray.