Turbulent Combustion Modeling Using Flamelet-Generated Manifolds for Gas Turbine Applications in OpenFOAM

Abstract

The continuous interest in reducing pollutions and developing both an efficient and clean combustion system require large attention in the design requirements, especially when related to industrial gas turbine application. Although in recent years the advancements in modelling have increased dramatically, combustion still needs a huge computational effort. The Flamelet-Generated Manifolds (FGM) method is considered a suitable solution with an accuracy that can be comparable with detailed chemistry simulations results. The full combustion system can be described by few controlling variables while the chemical details are stored in a database (manifold) as function of controlling variables. Transport equations are solved for the Navier-Stokes system and the controlling variables. The detailed chemistry code Chem1D is used to create the manifolds. Turbulence can be modeled using a PDF approach for the subgrid modeling of the chemistry terms. The OpenFOAM open source CFD package is used as CFD tool for the simulations. The aim of this work is to demonstrate the usage of FGM with OpenFOAM and figure out the status of the implementation. To achieve this goal, the work employs as test case a confined lean jet flame is used. For the case presented, an extensive experimental data set exist, including PIV and Raman data. Results are further compared with traditional methods, while FGM method might be easily extended to other scenarios.

Numerical Simulations of Heat Loss Effect on Premixed Jet Flame Using Flamelet Generated Manifold Combustion Model

“…The diagram shows that the combustion falls mainly in the thickened flame regime. This result is in agreement with unsteady simulations on this burner configuration [9][10][11], where turbulence was seen to impact the combustion significantly. This result does mean that the assumption that the flame resides in the flamelet regime is not strictly valid.…”

“…The FGM model stores detailed chemistry in a database so that it can be invoked as a function of a few controlling variables to obtain an accurate description of species concentrations and other thermo-chemical properties at reduced computational cost. Examples of the use of FGM can be found in the following papers: Bradley et al [4], Sorrentino et al [5], Mayrhofer et al [6], Perpignan et al [7], Donini et al [8], Fancello et al [9] and Proch and Kempf [10]. With the exception of [8,10] all authors applied FGM in a fully adiabatic approach or took heat loss into account but not its effect on chemical kinetics.…”

“…The DLR setup has been modelled using various iterations of the FGM model [8][9][10][11]. Donini et al [8] described the effect of heat loss and showed that an accurate representation of the temperature field can only be obtained by including this effect in the simulation.…”

Turbulent combustion modelling of a confined premixed jet flame including heat loss effects using tabulated chemistry

“…It was shown that for the current test case the addition of heat losses in the combustion model is essential to correctly predict the flame structure. Fancello et al [25] performed a LES simulation of the premixed jet flame using the FGM model in OpenFOAM and Proch et al [26] used the test case to validate different heat loss modelling approaches for FGM in the context of LES. The present work is a contribution to the modelling of the combustion dynamics of this test case, in which RANS and LES are systematically compared using the same turbulent combustion model and numerical methods.…”