An investigation on early evolution of soot in n-dodecane spray combustion using large eddy simulation

Large eddy simulation of soot formation and oxidation for different ambient temperatures and oxygen levels

“…This phenomenon is referred to soot spike and is well captured by the present LES model. Extensive discussion on the soot spike is available in the authors' previous study [38]. Further discussion regarding the variation of soot spike with the different ambient temperatures and O 2 levels are beyond the scope of the present work, and hence is presented in Appendix C. This rapid raise of the soot mass is similarly observed under different ambient O 2 levels and temperatures (cases 2 to 6).…”

“…The ratio of the resolved kinetic energy to the total kinetic energy in the spray region is 84%, indicating a sufficient resolution of the flow [39]. A full description of the convergence studies can be found in the authors' previous work [38].…”

“…A detailed explanation on the formation of soot spike was provided in the authors' previous work [38] for different oxygen levels at the ambient temperature of 900 K. As discussed in [38], the oxidation process becomes more dominant than the formation process due to the continually increasing OH radicals. This leads to a decrease in the total soot mass and, hence the formation of soot spike.…”

“…The corresponding descriptions and constants for these sub-processes are summarized in Table 5. The surface growth constant (𝐶 𝑠𝑔 ) is adjusted from 14 to 45 [38] in order to match the experimental soot mass provided in the ECN [11].…”

Large eddy simulation of transient combustion and soot recession in the ECN Spray A and D flames

“…The mesh convergence study for the Spray A case can be found in our previous work [35]. The local ratio of the resolved turbulent kinetic energy to the total turbulent kinetic energy is shown in Appendix A.…”