Large Eddy Simulation of Dispersed Two-Phase Flows and Premixed Combustion in IC-Engines

Author(s):  
D. Dimitrova ◽  
M. Braun ◽  
J. Janicka ◽  
A. Sadiki
Author(s):  
Enrica Masi ◽  
Benoiˆt Be´dat ◽  
Mathieu Moreau ◽  
Olivier Simonin

This paper presents an Euler-Euler Large-Eddy Simulation (LES) approach for the numerical modeling of non isothermal dispersed turbulent two-phase flows. The proposed approach is presented and validated by a priori tests from an Euler-Lagrange database, provided using discrete particle simulation (DPS) of the particle phase coupled with direct numerical simulation (DNS) of the turbulent carrier flow, in a non isothermal particle-laden temporal jet configuration. A statistical approach, the Mesoscopic Eulerian Formalism (MEF) [Fe´vrier et al., J. Fluid Mech., 2005, vol. 533, pp. 1–46], is used to write local and instantaneous Eulerian equations for the dispersed phase and then, by spatial averaging, to derive the LES equations governing the filtered variables. In this work, the MEF approach is extended to scalar variables transported by the particles in order to develop LES for reactive turbulent dispersed two-phase flows with mass and heat turbulent transport. This approach leads to separate the instantaneous particle temperature distribution in a Mesoscopic Eulerian field, shared by all the particles, and a Random Uncorrelated distribution which may be characterized in terms of Eulerian fields of particle moments such as the uncorrelated temperature variance. In this paper, the DPS-DNS numerical database is presented, LES Eulerian equations for the dispersed phase are derived in the frame of the Mesoscopic approach and models for the unresolved subgrid and random uncorrelated terms are proposed and a priori tested using the DPS-DNS database.


2007 ◽  
Vol 23 (6) ◽  
pp. 635-643 ◽  
Author(s):  
Xuelin Tang ◽  
Fujun Wang ◽  
Yulin Wu

2007 ◽  
Vol 33 (1) ◽  
pp. 1-39 ◽  
Author(s):  
E. Labourasse ◽  
D. Lacanette ◽  
A. Toutant ◽  
P. Lubin ◽  
S. Vincent ◽  
...  

Author(s):  
Tomoya Murota ◽  
Masaya Ohtsuka

To analyze combustion oscillation in the premixed combustor, a large-eddy simulation program for premixed combustion flow was developed. The subgrid scale (SGS) model of eddy viscosity type for compressible turbulence (Speziale et al., 1988) was adopted to treat the SGS fluxes. The fractal flamelet model, which utilizes the fractal properties of the turbulent premixed flame to obtain the reaction rate, was developed. Premixed combustion without oscillation was analyzed to verify the present method. The computational results showed good accordance with experimental data (Rydén et al., 1993). The combustion oscillation of an “established buzz” type in the premixed combustor (Langhorne, 1988) was also analyzed. The present method succeeded in capturing the oscillation accurately. The detailed mechanism was investigated. The appearance of the non-heat release region, which is generated because the supply of the unburnt gas into the combustion zone stagnates, and its disappearance play an important role.


Sign in / Sign up

Export Citation Format

Share Document