Numerical study of effect of ambient backpressure and temperature on spray characteristics of heavy fuel oil/n-butanol blend

In the present study, the influence of the backpressure and the ambient temperature on non-reacting and non-evaporating characteristics of heavy fuel oil (HFO)/n-butanol blend at the injection pressure of 600 (bar) is numerically studied. Three different backpressures of 1, 14 and 28 bar and two different ambient temperatures of 298 K and 498 K have been considered in the combustion chamber of the medium speed engine. For the simulation of the liquid phase of the fuel interaction with the continuous air phase, an Eulerian-Lagrangian multiphase scheme was implemented. The open-source CFD toolbox of OpenFOAM was used for the present study. Due to the lack of experimental data in the context for HFO/n-butanol characteristics, the mesh resolution sensitivity analysis of C14H30 as a HFO at the injection pressure of 600 (bar) was carried out. Consequently, numerical results of the spray penetration length and the spray cone angle were validated by available experimental data with RMS of 3.34 and 0.905, respectively. Based on computational results, an increase in the backpressure from 1 to 14 (bar) decreased the spray penetration length, enhanced the spray cone angle, while reduced the SMD. Furthermore, due to the increase in the ambient temperature, the spray penetration length increased, while the SMD decreased.