Introduction: Combustion Modeling and Large Eddy Simulation: Development and Validation Needs for Gas Turbines.

AIAA Journal ◽  
2006 ◽  
Vol 44 (4) ◽  
pp. 673-673 ◽  
Author(s):  
Fernando F. Grinstein ◽  
Nan-Suey Liu ◽  
Joseph C. Oefelein
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbines ◽  
Combustion Modeling ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Development And Validation

scholarly journals Investigation of the Turbulent Near Wall Flame Behavior for a Sidewall Quenching Burner by Means of a Large Eddy Simulation and Tabulated Chemistry

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 65 ◽  
Author(s):  
Arne Heinrich ◽  
Guido Kuenne ◽  
Sebastian Ganter ◽  
Christian Hasse ◽  
Johannes Janicka
Keyword(s):  
Heat Flux ◽  
Large Eddy Simulation ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Heat Fluxes ◽  
Maximum Heat ◽  
Eddy Simulation ◽  
Tabulated Chemistry ◽  
Large Eddy ◽  
Near Wall

Combustion will play a major part in fulfilling the world’s energy demand in the next 20 years. Therefore, it is necessary to understand the fundamentals of the flame–wall interaction (FWI), which takes place in internal combustion engines or gas turbines. The FWI can increase heat losses, increase pollutant formations and lowers efficiencies. In this work, a Large Eddy Simulation combined with a tabulated chemistry approach is used to investigate the transient near wall behavior of a turbulent premixed stoichiometric methane flame. This sidewall quenching configuration is based on an experimental burner with non-homogeneous turbulence and an actively cooled wall. The burner was used in a previous study for validation purposes. The transient behavior of the movement of the flame tip is analyzed by categorizing it into three different scenarios: an upstream, a downstream and a jump-like upstream movement. The distributions of the wall heat flux, the quenching distance or the detachment of the maximum heat flux and the quenching point are strongly dependent on this movement. The highest heat fluxes appear mostly at the jump-like movement because the flame behaves locally like a head-on quenching flame.

On the Combination of Large Eddy Simulation and Phenomenological Soot Modelling to Calculate the Smoke Index From Aero-Engines Over a Large Range of Operating Conditions

2017 ◽  
Author(s):  
Jean Lamouroux ◽  
Stéphane Richard ◽  
Quentin Malé ◽  
Gabriel Staffelbach ◽  
Antoine Dauptain ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbines ◽  
Soot Formation ◽  
Operating Conditions ◽  
Extended Model ◽  
Eddy Simulation ◽  
Design Office ◽  
Wide Range ◽  
Large Eddy ◽  
Aero Engines

Nowadays, models predicting soot emissions are, neither able to describe correctly fine effects of technological changes on sooting trends nor sufficiently validated at relevant operating conditions to match design office quantification needs. Yet, phenomenological descriptions of soot formation, containing key ingredients for soot modeling exist in the literature, such as the well-known Leung et al. model (Combust Flame 1991). This approach indeed includes contributions of nucleation, surface growth, coagulation, oxidation and thermophoretic transport of soot. When blindly applied to aeronautical combustors for different operating conditions, this model fails to hierarchize operating points compared to experimental measurements. The objective of this work is to propose an extension of the Leung model, including an identification of its constants over a wide range of condition relevant of gas turbines operation. Today, the identification process can hardly be based on laboratory flames since few detailed experimental data are available for heavy-fuels at high pressure. Thus, it is decided to directly target smoke number values measured at the engine exhaust for a variety of combustors and operating conditions from idling to take-off. A Large Eddy Simulation approach is retained for its intrinsic ability to reproduce finely unsteady behavior, mixing and intermittency. In this framework, The Leung model for soot is coupled to the TFLES model for combustion. It is shown that pressure-sensitive laws for the modelling constant of the soot surface chemistry are sufficient to reproduce engine emissions. Grid convergence is carried out to verify the robustness of the proposed approach. Several cases are then computed blindly to assess the prediction capabilities of the extended model. This study paves the way for the systematic use of a high fidelity tool solution in design office constraints for combustion chamber development.

Large eddy simulation applications in gas turbines

2009 ◽  
Vol 367 (1899) ◽  
pp. 2827-2838 ◽  
Author(s):  
Kevin Menzies
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Complex Geometry ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Wide Range ◽  
Large Eddy ◽  
Design Cycle ◽  
Flow Phenomena

The gas turbine presents significant challenges to any computational fluid dynamics techniques. The combination of a wide range of flow phenomena with complex geometry is difficult to model in the context of Reynolds-averaged Navier–Stokes (RANS) solvers. We review the potential for large eddy simulation (LES) in modelling the flow in the different components of the gas turbine during a practical engineering design cycle. We show that while LES has demonstrated considerable promise for reliable prediction of many flows in the engine that are difficult for RANS it is not a panacea and considerable application challenges remain. However, for many flows, especially those dominated by shear layer mixing such as in combustion chambers and exhausts, LES has demonstrated a clear superiority over RANS for moderately complex geometries although at significantly higher cost which will remain an issue in making the calculations relevant within the design cycle.

Application of Large-Eddy Simulation and the Multi-Scalar Flamelet Approach to a Methane-Hydrogen Mixed-Combustion-Type Industrial Gas-Turbine Combustor

2017 ◽  
Author(s):  
Ryosuke Kishine ◽  
Tenshi Sasaki ◽  
Nobuyuki Oshima ◽  
Saad Sibawayh ◽  
Kohshi Hirano ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Flame Temperature ◽  
Simulation Method ◽  
Eddy Simulation ◽  
Development Costs ◽  
Large Eddy ◽  
Inflow Condition ◽  
Industrial Gas Turbine

In pursuit of a reduction in environmental loading, gas turbines equipped with lean premixed combustor technology that use a hydrogen-enriched fuel instead of pure methane have entered practical service. An accurate numerical simulation method is therefore needed to reduce product-development costs to a minimum. We performed a numerical analysis of an industrial combustor with a mixed methane-hydrogen fuel by large-eddy simulation and extending the 2-scalar flamelet approach to a multi-scalar one. The calculation object was the combustor of an L30A-DLE gas-turbine. Two calculations were conducted with different fuel compositions at the supplemental burner. In the first simulation, the inflow gas was composed of methane and air, whereas in the second simulation, the inflow gas was composed of methane, air, and hydrogen. The inlet boundary conditions were set so that both cases have the same adiabatic flame temperature at the outlet. The temperature distributions throughout the combustor were approximately equal in both cases. This study therefore suggests that equivalent performance can be obtained by setting the inflow condition at the supplemental burner so that the outlet adiabatic temperatures are equal for both monofuel combustion and mixed combustion.

Temperature Ratio Effects on Bluff-Body Wake Dynamics Using Large Eddy Simulation and Proper Orthogonal Decomposition

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Ryan Blanchard ◽  
Wing Ng ◽  
Uri Vandsburger
Keyword(s):  
Large Eddy Simulation ◽  
Heat Release ◽  
Proper Orthogonal Decomposition ◽  
Gas Turbines ◽  
Bluff Body ◽  
Orthogonal Decomposition ◽  
Combustion Dynamics ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Proper Orthogonal

In this article, we describe the use of proper orthogonal decomposition (POD) to investigate how the dominant wake structures of a bluff-body-stabilized turbulent premixed flame are affected by the heat released by the flame itself. The investigation uses a validated large eddy simulation (LES) to simulate the dynamics of the bluff-body's wake (Blanchard et al., 2014, “Simulating Bluff-Body Flameholders: On the Use of Proper Orthogonal Decomposition for Wake Dynamics Validation,” ASME J. Eng. Gas Turbines Power, 136(12), p. 122603; Blanchard et al., 2014, “Simulating Bluff-Body Flameholders: On the Use of Proper Orthogonal Decomposition for Combustion Dynamics Validation,” ASME J. Eng. Gas Turbines Power, 136(12), p. 121504). The numerical simulations allow the effect of heat release, shown as the ratio of the burned to unburned temperatures, to be varied independently from the Damköhler number. Five simulations are reported with varying fractions of the heat release ranging from 0% to 100% of the value of the baseline experiment. The results indicate similar trends reported qualitatively by others, but by using POD to isolate the dominant heat release modes of each simulation, the decomposed data can clearly show how the previously reported flow structures transition from asymmetric shedding in the case of zero heat-release to a much weaker, but fully symmetric shedding mode in the case of full heat release with a much more elongated and stable wake.

Aerothermal Prediction of an Aeronautical Combustion Chamber Based on the Coupling of Large Eddy Simulation, Solid Conduction and Radiation Solvers

2015 ◽  
Author(s):  
Sandrine Berger ◽  
Stéphane Richard ◽  
Gabriel Staffelbach ◽  
Florent Duchaine ◽  
Laurent Gicquel
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Thermal Environment ◽  
Heat Fluxes ◽  
High Fidelity ◽  
Eddy Simulation ◽  
Precise Knowledge ◽  
Large Eddy

A precise knowledge of the thermal environment is essential for gas turbines design. Combustion chamber walls in particular are subject to strong thermal constraints. It is thus essential for designers to characterize accurately the local thermal state of such devices. Today, the determination of wall temperatures is performed experimentally by complex thermocolor tests. To limit such expensive experiments and integrate the knowledge of the thermal environment earlier in the design process, efforts are currently performed to provide high fidelity numerical tools able to predict the combustion chamber walls temperature. Many coupled physical phenomena are involved: turbulent combustion, convection and mixing of hot products and cold flows, conduction in the solid parts as well as gas to gas, gas to wall and wall to wall radiative transfers. The resolution of such a multiphysics problem jointly in the fluid and the solid domains can be done numerically through the use of several dedicated numerical and algorithmic approaches. In this paper, a partitioned coupling methodology is used to investigate the solid steady state wall temperature of a helicopter combustor in take-off conditions. The methodology relies on a high fidelity Large Eddy Simulation reacting flow solver coupled to conduction and radiative solvers. Different computations are presented in order to assess the role of each heat transfer process in the temperature field. A conjugate heat transfer simulation is first proposed and compared with experimental thermocolor tests. The effect of radiation is then investigated comparing relative importance of convective and radiative heat fluxes.

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