Numerical simulation of combustion instabilities in Jet_Engine combustion chamber
Jean-Philippe LegierCERFACS - These
Jeudi 13 Decembre 2001 - 14h30, CERFACS Conference Room
Abstract :
NUMERICAL SIMULATION OF COMBUSTION INSTABILITIES IN JET_ENGINE COMBUSTION CHAMBER
Reactive unsteady phenomena such as combustion instabilities have to be understood in order to build new and efficient combustion chambers. These phenomena can be numericaly studied with large eddy simulation associated to combustion models.
This thesis presents the dynamic thickened flame model and the kinetic scheme PEA developed to take into account the specificities of reaction and flow in aeronautical burner: mixing zones, diffusion and premixed flames with various equivalence ratio. These models are implemented in the parallel code AVBP described in chapter 3.
They were validated by the study of a 2D propane/air burner, set up at EM2C laboratory (Chatenay Malabry). Mean flow fields have been compared to experimental results and the unsteady flame response due to perturbation is also evaluated. To do so, the interaction index n and the flame delay t is calculated experimentally and numerically with the same method, which is an originality and a key point of this work. A direct comparison of instantaneous velocity and reaction rate fields has also been done. These comparisons validated the use of LES and dynamic thickened flame models to study and predict combustion instabilities.
Finally, the simulation of an industrial configuration such as a typical Lean Premixed Prevaporized (LPP) device shows that LES and combustion models can compute the flow field in a complex geometry. Flame positions of two combustion regimes simulated with LES are similar to those observed experimentally .
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