Investigation of the Engine Combustion Network Spray C Characteristics at High Temperature and High-Pressure Conditions Using Eulerian Model

The morphology of the internal flow of Spray C was numerically investigated using an Eulerian volume-of-fluid (VOF) method in the finite-volume framework. The injector geometry available in the Engine Combustion Network (ECN) was employed, and the simulations were performed under the ambient condition at 900 K and 60 bar. The simulation data were analyzed for three important events: the initial nozzle opening, steady injection, and nozzle closing. First, projected densities on XY and XZ planes are computed radially at four axial locations. Projected density at 2 mm is compared with available experimental results, which show similar results. Then, the mass flow rate is found to match the reported experimental results and the virtually generated values from CMT using an appropriate discharge coefficient. An investigation on the appropriate discharge coefficient is performed and found that C_d = 0.63 ± 0.02 is acceptable for Spray C. A grid-convergent study revealed that the predicted cavitation formation process was significantly affected by various grid sizes. Based on this study, a minimum mesh size of 7.8 μm was needed to reproduce the experimental observation properly. The predicted flow characteristics at the sharper edge at 0° and the smooth edge at 180° degrees showed comparable trends to the experimental data at the same injection pressure but different ambient pressure.