Eulerian - Eulerian Large Eddy Simulations Applied to Non-Reactive Transient Diesel Sprays.

Abstract : The aim of this study is to perform and analyze LES (Large Eddy Simulations) simulations of transient Diesel sprays in a high-pressure and high-temperature vessel. In order to be representative of real Diesel injection strategies, two cases are investigated: the first one corresponds to a single injection, while a double injection is performed in the second case. For each case, numerous realizations are computed to retrieve average values and fluctuations of fuel concentration. A mesh refinement sensitivity analysis is conducted to assess the quality of the LES by comparing numerical fuel mass fraction profiles with experimental ones. This comparison is then extended to spray angles and vapor penetrations. The influence of injection boundary conditions such as injection rate profile and injection delay, on transient LES results is then evaluated. Finally, guidelines for simulating transient Diesel sprays in engines with LES are proposed.