Abstract:
This work includes the numerical investigation of experimental work, which includes
the modeling turbulent partially premixed flames and analysis of real combustor. This
mode of combustion involves many physical complexities such as flame propagation in an
unevenly premixed mixture of fuel and oxidizer, and turbulence/chemistry interaction
in the presence of mixture fraction gradients. The underlying physics that describes the
phenomena is very complicated and still not fully understood, thus creating significant
modeling challenges for the researchers.
This work addresses these issues by using a joint probability density function (PDF)
approach with Detached Eddy Simulation (DES). It describes the Joint PDF by a
parameter, mixture fraction, describing mixing and progress variable. This modeling
framework is validated by using an experimental test case in this study, including a
practical swirling flame, exhibiting strong partial premixing features. The simulation
results calculated for various validation cases show the model performance for a broad
range of flows and mixing conditions, with an attractive computational cost for practical
interests.
We assess validity of the DES model for a confined swirling flame with the empirical
data. The simulation results are compared against an extensive experimental data-set
including velocity, mixture fraction, temperature and major species mass fraction measurements,
showing an overall good agreement at various locations inside the combustion
chamber. Our work shows that the DES model predicts the intermediate species mass
fraction reasonably well.
The study of real combustor involves the modeling of finite-rate model along with DES
as physical model in a turbojet combustor. The finite-rate describes the chemical source
term by using Arrhenius expressions without turbulent fluctuations. The modeling
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framework is based on numerical simulation which is rich-burn quick lean combustion.
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