Real-fluid injection modeling and LES simulation of the ECN Spray A injector using a fully compressible two-phase flow approach
Résumé
10 A fully compressible two-phase flow model consisting of four balance equations including two mass, one 11 momentum, and one internal energy equation, formulated with the mechanical and thermal equilibrium 12 assumptions is developed in this article. This model is closed with a real fluid equation of state (EoS) and 13 has been applied to the simulation of different 1D academic cases, in addition to the 3D Large-Eddy 14 Simulation (LES) of the Engine Combustion Network (ECN) Spray A injector including the needle to 15 target part with and without the phase change (i.e. frozen) assumptions. The obtained numerical results 16 from the model with phase change have proven to be able to accurately predict the liquid, vapor 17 penetrations and rate of injection compared to experimental data. However, the frozen model has 18 presented some uncertainties and deviations in predicting the penetration length as with different measure 19 criterions, even though an excellent agreement can be achieved in the estimation of rate of injection, near-20 nozzle mass and velocity distribution. Several conclusions are drawn from the simulations: (1) the initial 21 in-nozzle flow has a strong effect on the early jet development; (2) considering phase change is still 22 essential in the high temperature, high pressure (HTHP) injection modelling since it strongly affects the 23 temperature distribution, turbulence intensity and thereby the jet development; (3) significant variations of 24 liquid compressibility factor and density, as well as the cooling effect through the nozzle are highlighted. 25 Overall, the detailed analysis of the numerical results reported in this article may complement the Engine 26 Combustion Network (ECN) experimental database. 27 28
Origine : Fichiers produits par l'(les) auteur(s)