scholarly journals Large Eddy Simulation of a Bluff Body Stabilized Lean Premixed Flame

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
A. Andreini ◽  
C. Bianchini ◽  
A. Innocenti
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Combustion ◽  
Bluff Body ◽  
Sensitivity Study ◽  
Flame Stabilization ◽  
Combustion Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Lean Premixed

The present study is devoted to verify current capabilities of Large Eddy Simulation (LES) methodology in the modeling of lean premixed flames in the typical turbulent combustion regime of Dry LowNOxgas turbine combustors. A relatively simple reactive test case, presenting all main aspects of turbulent combustion interaction and flame stabilization of gas turbine lean premixed combustors, was chosen as an affordable test to evaluate the feasibility of the technique also in more complex test cases. A comparison between LES and RANS modeling approach is performed in order to discuss modeling requirements, possible gains, and computational overloads associated with the former. Such comparison comprehends a sensitivity study to mesh refinement and combustion model characteristic constants, computational costs, and robustness of the approach. In order to expand the overview on different methods simulations were performed with both commercial and open-source codes switching from quasi-2D to fully 3D computations.

Large Eddy Simulation of a Gas-Turbine Combustor Using 2-Scalar Flamelet Approach

2007 ◽  
Author(s):  
Takuji Nakashima ◽  
Nobuyuki Oshima
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Combustion ◽  
Numerical Prediction ◽  
Premixed Combustion ◽  
Combustion Reaction ◽  
Combustion Model ◽  
Gas Turbine Combustor ◽  
Eddy Simulation ◽  
Large Eddy

To investigate the ability of a numerical prediction method in a practical combustor system, we have conducted a numerical simulation of partially premixed turbulent combustion within a gas-turbine combustor geometry. A combination of Large-Eddy simulation and the 2-scalar flamelet approach are used to simulate unsteady turbulent combustion in modeling turbulent and combustion reaction phenomena and their interactions. With the successful simulation of both the premixed and non-premixed combustion states including the effects of turbulence, the predicted distributions of time-averaged temperature and the O2 mole fraction are found to essentially correspond to the experimental data. In an analysis of the predicted results, the weights of resolved and unresolved phenomena in the numerical prediction are estimated in order to discuss the effects of the turbulent combustion model applied to a practical combustion flow. The analysis determines the effect of turbulence on a Grid Scale that accelerates the premixed combustion reaction, while the modeled effect of turbulence caused by combustion acceleration as shown on a Sub-grid Scale is about twice of the effect as that seen on the Grid Scale.

scholarly journals Study of the Wall Thermal Condition Effect in a Lean-Premixed Downscaled Can Combustor Using Large-Eddy Simulation

2016 ◽  
Author(s):  
D. Mira ◽  
M. Vázquez ◽  
G. Houzeaux ◽  
S. Gövert ◽  
J. W. B. Kok ◽  
...  
Keyword(s):  
Turbulent Combustion ◽  
Mixture Fraction ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Laminar Flames ◽  
Combustion Model ◽  
Test Case ◽  
Eddy Simulation ◽  
Condition Effect ◽  
Large Eddy

The primary purpose of this study is to evaluate the ability of LES, with a turbulent combustion model based on steady flamelets, to predict the flame stabilization mechanisms in an industrial can combustor at full load conditions. The test case corresponds to the downscaled Siemens can combustor tested in the high pressure rig at the DLR. The effects of the wall temperature on the prediction capabilities of the codes is investigated by imposing several heat transfer conditions at the pilot and chamber walls. The codes used for this work are Alya and OpenFOAM, which are well established CFD codes in the fluid mechanics community. Prior to the simulation, results for 1-D laminar flames at the operating conditions of the combustor are compared with the detailed solutions. Subsequently, results from both codes at the mid-plane are compared against the experimental data available. Acceptable results are obtained for the axial velocity, while discrepancies are more evident for the mixture fraction and the temperature, particularly with Alya. However, both codes showed that the heat losses influence the size and length of the pilot and main flame.

Large-Eddy Simulation of Bluff-Body Flame Using the Equilibrium Combustion Model

2015 ◽  
Vol 29 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Shafiq R. Qureshi ◽  
Waqar A. Khan ◽  
Robert Prosser
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Combustion Model ◽  
Eddy Simulation ◽  
Large Eddy

Large Eddy Simulation to Predict Flame Front Position for Turbulent Lean Premixed Jet Flame at High Pressure

2018 ◽  
Author(s):  
Keita Yunoki ◽  
Tomoya Murota
Keyword(s):  
High Pressure ◽  
Large Eddy Simulation ◽  
Flame Front ◽  
Combustion Model ◽  
Test Results ◽  
Jet Flame ◽  
Eddy Simulation ◽  
Front Position ◽  
Large Eddy ◽  
Lean Premixed

To predict the flame front position, we adopt the large eddy simulation (LES) and incorporate into it a combustion model, the hybrid turbulent combustion model (HTC model), applicable to any flame mode. We take previously obtained test results for the axisymmetric jet lean premixed flame in a cylindrical chamber at high pressure and investigate the effects of equivalence ratio variation on flame front positions. Full details of these tests are available in the literature. We find the simulation results of the axial positions of the flame front points, defined by the inflection point of the OH concentration distributions, show good agreement with test results (less than 4% difference between them). Therefore, we conclude that the HTC model is capable of capturing the actually observed tendency when changing the equivalence ratios and that the combination of the HTC model with LES suggests that flame stretch effect is important to predict the flame front position for lean premixed combustion.

scholarly journals Large Eddy Simulation of Bluff-Body Flame Approaching Blow-Off: A Sensitivity Study

2018 ◽  
Vol 191 (10) ◽  
pp. 1815-1842
Author(s):  
Erdzan Hodzic ◽  
Mehdi Jangi ◽  
Robert-Zoltan Szasz ◽  
Christophe Duwig ◽  
Marco Geron ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Sensitivity Study ◽  
Eddy Simulation ◽  
Large Eddy

Large Eddy Simulation of Turbulent Combustion Flows in Gas Turbine Combustor

2002 ◽  
Author(s):  
Takuji Tominaga ◽  
Nobuyuki Taniguchi ◽  
Yuichi Itoh ◽  
Toshio Kobayashi
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Combustion ◽  
Equivalence Ratio ◽  
Equation Model ◽  
Gas Turbine Combustor ◽  
Turbine Engine ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Annular Combustor

In this paper, Large Eddy Simulation (LES) and G-equation model based on flamelet concept are demonstrated in axially staged annular combustor of gas turbine engine. G-equation model is extended for combustion in a non-uniform equivalence ratio of premixed gas. Using this model, the simulations of the flame propagation are executed with different spatial distribution of the equivalence ratios. In order to compare the results, experiments for combustion and non-combustion flows in the modeled combustor are also performed. The flow field can be predicted by LES and be agreed with the experimental results essentially. The flame propagating behaviors depending on the equivalence ratios are represented by the extended G-equation model.

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