Large eddy simulation of turbulent reacting flows using Cartesian grid and boundary corrections

1998 ◽  
Author(s):  
J. Gullbrand ◽  
X. Bai ◽  
L. Fuchs
Keyword(s):  
Large Eddy Simulation ◽  
Reacting Flows ◽  
Cartesian Grid ◽  
Turbulent Reacting Flows ◽  
Eddy Simulation ◽  
Large Eddy

Local Entropy Generation in Large Eddy Simulation of Turbulent Reacting Flows

2017 ◽  
Author(s):  
Mehdi Safari
Keyword(s):  
Large Eddy Simulation ◽  
Entropy Generation ◽  
Reacting Flows ◽  
Chemical Mechanism ◽  
Turbulent Reacting Flows ◽  
Local Entropy ◽  
Source Terms ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Local Entropy Generation

Analysis of local entropy generation is an effective means to investigate sources of efficiency loss in turbulent combustion from the standpoint of the second law of thermodynamics. A methodology, termed the entropy filtered density function (En-FDF), is developed for large eddy simulation (LES) of turbulent reacting flows to include the transport of entropy, which embodies the complete statistical information about entropy variations within the subgrid scale. The modeled En-FDF contains a stochastic differential equation (SDE) for entropy which is solved by a Lagrangian Monte Carlo method. In this study, a numerical study has been done on effectiveness of SDE to model entropy variation using a partially stirred reactor (PaSR). This provides a computationally affordable case to compare different effects of entropy generation source terms and fine tune mixing coefficients. In this equation, turbulent mixing is modeled with Interaction by Exchange with the Mean (IEM). Combustion source terms are provided by direct integration of a GRI3.0 mechanism for methane/air system. Evolution of entropy was calculated from stochastic model and then compared with the one obtained directly by integrating the chemical mechanism. It was shown that results of both calculations have very good agreement versus different mixture fractions.

Review of Large-Eddy Simulation of Non-Premixed Turbulent Combustion

2004 ◽  
Vol 128 (2) ◽  
pp. 209-215 ◽  
Author(s):  
James J. Riley
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Combustion ◽  
Mixture Fraction ◽  
Reacting Flows ◽  
Turbulent Reacting Flows ◽  
Premixed Turbulent Combustion ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Recent Developments ◽  
Potential Use

Recent developments in the methodology of large-eddy simulation applied to turbulent, reacting flows are reviewed, with specific emphasis on mixture-fraction-based approaches to nonpremixed reactions. Some typical results are presented, and the potential use of the methodology in applications and the future outlook are discussed.

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