A
Prognosis Technique for Turbulent Combustion
Funded by: German Research Foundation (DFG) and Fluent Inc.
Objective: Detailed turbulent flame calculations based on the FLUENT
PDF combustion code
Method: A comparison of Delft III flame computations and measurements
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The right picture shows the Delft Burner in an experimental
setup for species concentration measurements with the LDA method. The main
fuel is natural gas and the oxidizer is air. The resulting non-premixed
flame shows strong coupling effects between the turbulence and chemistry.
It is, therefore, well appropriate to investigate the performance of
numerical models. To stabilize the flame on the burner head, the burner
generates 12 premixed pilot flames (left picture). The hot products ignite
the main fuel and avoid a lift off of the diffusion flame.
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A temperature contour plot of 3-dimensional PDF calculations with 25
species is given. The middle plane, a perpendicular plane in the region of
the pilot flames and the hot region of the pilot flames are shown. The
computational grid consists of 500 000 cells. The simulations were
performed with the FLUENT code on 16 parallel nodes at the
LINUX cluster of the Mathematics
Department of the University of Wyoming. |
| Detailed simulations of
the Delft III flame are computationally expensive so that 2-dimensional
computations are required to simulate the whole domain of the flame. A
basic problem of such calculations is the treatment of the influence of
the pilot flames, which was shown to have a very significant effect on
model results. To overcome this problem one has to combine 2-dimensional
calculations of all the flame with 3-dimensional pilot flame calculations.
We performed such 3-dimensional pilot flame calculations in order
to explain the structure of this flow. |
Disclaimer
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