Abstract
Large-eddy simulation is applied for the simulation of n-dodecane split injections with 0.5-ms dwell time. The objective is to study the interactions between the flame induced by the first injection and the secondly injected spray. The local flow and flame structure in split injections are also connected with each other. Results show that an increase in axial velocity can be seen for the second injection owing to the decrease in density and the effect of gas expansion. And combustion prevents the entrainment of air, leading to fuel-rich ignition. High-temperature reaction regions move to fuel-richer regions for the second injection. After that, the effects of the initial temperature and first injection duration on the combustion process are further discussed. By decreasing the initial temperature, the time when the maximum species mass fraction, including hydrogen peroxide, formaldehyde, and hydroxyl, starting to increase is delayed. By reducing the injected fuel during the first injection, the maximum mass fraction profiles for hydrogen peroxide and formaldehyde decline earlier, indicating that they are consumed very quickly without sufficient production. Finally, chemical explosive mode analysis indicates that combustion of the second spray is controlled by mixing.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 119214 |
| Journal | Fuel |
| Volume | 285 |
| DOIs | |
| State | Published - Sep 19 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: The work was supported by National Natural Science Foundation of China (Grant Nos. 91741119, 51606133, 91641203) and Marine Low-Speed Engine Project (Phase I). This work was supported by the National Science Fund for Distinguished Young Scholars (Grant No. 51825603). The work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1 (A).