Numerical Simulation of the Dynamics of Turbulent Swirling Flames

8 Outlook
The present study shows the potential of the LES/SI method to identify the
flame response for fully premixed conditions. The following ideas are proposed
as outlook to this work:
• In technical applications, as in operating gas turbines, the mixing between
fuel and air is produced moments before reaction occurs. Thus, the
flame reacts in most cases under the presence of mixture inhomogeneity.
The impact of equivalence ratio fluctuations on the flame response was
investigated previously by Huber and Polifke [85] in a RANS context as a
MISO system. Application of the method on the LES context is planned
in future investigations.
• Investigation of the impact of operating pressure and multi-burner configurations
on the flame dynamics. These conditions are typical in industrial
gas turbines, and not considered in this study.
• It is recommended to investigate the flame dynamics using the same
burner with different combustion models and mesh resolution. Most industrial
applications are usually simulated with a lower level of mesh resolution
due the limited availability of computational resources. Investigations
to quantify the impact on the flame response by the lower mesh
resolution have not been carried out.
• The separation of the flame response to axial and swirl fluctuations. The
system can be analyzed as a MISO system to identify the contributions in
the flame response from mass flow and swirl fluctuations separately.
• For the prediction of limit cycle amplitudes from stability analysis, it is
necessary to introduce the non-linear behavior of the flame with dependence
of the perturbation amplitude by the flame describing func-
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