Naslov
CFD modelling of spray and combustion process using avl FIRE

Autori
Petranović, Zvonimir ; Edelbauer, Wilfried ; Vujanović, Milan ; Duić, Neven ; Priesching, Peter ; Tatschl, Reinhard

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Digital Proceedings of The 36th International Symposium on Combustion / - , 2016

Skup
36th International Symposium on Combustion

Mjesto i datum
COEX, Seoul, Korea, 31.07.2016. - 05.08.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
CFD modelling; Eulerian; Lagrangian; coupling; ELSA; combustion; Nozzle flow

Sažetak
The common and widely used method for spray calculation is the Lagrangian DDM approach. In this model the gaseous phase is considered as continuum whilst the liquid phase is represented by group of droplets called parcels. The DDM model is numerically efficient but has several disadvantages for solving the dense spray region. To overcome disadvantages, an Eulerian droplet size class (DSC) method is developed. Within this model, both the liquid and the gaseous phases, are considered as continuum. The Eulerian DSC method is computationally more expensive but gives a good representation of the dense, near nozzle, region. To take advantage of both, the Eulerian DSC and Lagrangian DDM method, they can be combined through the AVL Code Coupling Interface (ACCI). The advantage of such approach is retaining a high CPU efficiency, characteristic for the DDM method, with an increased solution accuracy in the near-nozzle region characteristic for the DSC method. The alternative to the ACCI approach would be the Eulerian-Lagrangian spray atomization (ELSA) model which has been under constant development. The main difference between the ELSA spray model and the ACCI approach is that in the ELSA model, in the vicinity of the nozzle, the gas and the liquid phase are considered as one mixture phase. The DDM method and the ACCI approach were used for simulations of real engine configurations. Seven cases representing seven engine operation points were simulated, and the influence of swirl intensity, injection timing, EGR composition, etc. on the pollutant emissions was researched. The DSC method was used for investigation of high pressure liquid fuel injection into a constant volume chamber. In this approach the combustion process is described by solving general gas phase reactions. The simulation results of liquid and vapor fuel axial/radial penetration, lift-off length and ignition delay, mixture and temperature field were compared to the available experimental data. The ELSA spray model was used together with a real representation of the inflow boundary condition. The influence of the non-symmetrical flow developed within the nozzle hole channel on the spray shape was successfully captured.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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