Large-eddy simulation of a multi-injection flame in a diesel engine environment using an unsteady flamelet/progress variable approach

2021 ◽  
Vol 33 (10) ◽  
pp. 105107
Author(s):  
Xu Wen ◽  
Sandro Gierth ◽  
Martin Rieth ◽  
Jacqueline H. Chen ◽  
Christian Hasse
2021 ◽  
Author(s):  
Lorenzo Angelilli ◽  
Pietro Paolo Ciottoli ◽  
Riccardo Malpica Galassi ◽  
Francisco E. Hernandez Perez ◽  
Mattia Soldan ◽  
...  

2005 ◽  
Vol 73 (3) ◽  
pp. 374-381 ◽  
Author(s):  
K. Mahesh ◽  
G. Constantinescu ◽  
S. Apte ◽  
G. Iaccarino ◽  
F. Ham ◽  
...  

Large-eddy simulation (LES) has traditionally been restricted to fairly simple geometries. This paper discusses LES of reacting flows in geometries as complex as commercial gas turbine engine combustors. The incompressible algorithm developed by Mahesh et al. (J. Comput. Phys., 2004, 197, 215–240) is extended to the zero Mach number equations with heat release. Chemical reactions are modeled using the flamelet/progress variable approach of Pierce and Moin (J. Fluid Mech., 2004, 504, 73–97). The simulations are validated against experiment for methane-air combustion in a coaxial geometry, and jet-A surrogate/air combustion in a gas-turbine combustor geometry.


2020 ◽  
Vol 31 (10) ◽  
pp. 4253-4274
Author(s):  
Shota Akaotsu ◽  
Yohsuke Matsushita ◽  
Hideyuki Aoki ◽  
Weeratunge Malalasekera

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Rohit Kulkarni ◽  
Wolfgang Polifke

The potential of a progress variable formulation for predicting autoignition and subsequent kernel development in a nonpremixed jet flame is explored in the LES (Large Eddy Simulation) context. The chemistry is tabulated as a function of mixture fraction and a composite progress variable, which is defined as a combination of an intermediate and a product species. Transport equations are solved for mixture fraction and progress variable. The filtered mean source term for the progress variable is closed using a probability density function of presumed shape for the mixture fraction. Subgrid fluctuations of the progress variable conditioned on the mixture fraction are neglected. A diluted hydrogen jet issuing into a turbulent coflow of preheated air is chosen as a test case. The model predicts ignition lengths and subsequent kernel growth in good agreement with experiment without any adjustment of model parameters. The autoignition length predicted by the model depends noticeably on the chemical mechanism which the tabulated chemistry is based on. Compared to models using detailed chemistry, significant reduction in computational costs can be realized with the progress variable formulation.


2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Akihiro Kishimoto ◽  
Hideki Moriai ◽  
Kenichiro Takenaka ◽  
Takayuki Nishiie ◽  
Masaki Adachi ◽  
...  

A new nonadiabatic procedure of the flamelet/progress-variable approach (NA-FPV approach) is proposed, and the validity is assessed by performing a large eddy simulation (LES) employing the NA-FPV approach for an H2/O2 combustion field in a single element coaxial combustor under a pressurized condition. The results show that the LES employing the NA-FPV approach can successfully predict the heat flux and capture the effects of heat loss through the cooled walls on the combustion characteristics. This procedure is quite useful especially for the numerical simulations of combustion fields with high temperatures, where there remain reactive radicals (e.g., OH, CH) with high concentrations, such as pressurized combustion, supercritical combustion, and oxygen combustion.


2020 ◽  
Vol 163 ◽  
pp. 104843
Author(s):  
Zhengwei Gao ◽  
Haiou Wang ◽  
Changcheng Song ◽  
Kun Luo ◽  
Jianren Fan

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