497217.pdf (87.74 MB)
Unsteady flamelet modelling of turbulent non-premixed combustion
thesis
posted on 2011-02-17, 15:28 authored by Anand OdedraIn this study, RANS based axisymmetric simulations of the jet flames, bluffbody
flames and swirling flames have been attempted by employing steady and
unsteady flamelet models. The jet flames have been studied for pure hydrogen
and diluted hydrogen (CO/H2/N2) fuels. The bluff-body flames have been studied
for three different fuels CH4/H2, H2/CO and CH3OH. The swirling flame has
been investigated for CH4/H2 fuel. The importance of unsteady effects is
thoroughly assessed for combustion predictions. The transient effects are
considered in a post-processing manner employing the Lagrangian Flamelet
Model (LFM) for jet flames and the Eulerian Particle Flamelet Model (EPFM)
for recirculating bluff-body and swirling flames. The LFM is valid for parabolic
flows and uses Lagrangian residence time to calculate transient flamelets. The
EPFM can be applied to both parabolic and elliptical flows. In the EPFM, the
transient history of scalar dissipation rate, conditioned at stoichiometric mixture
fraction is required to generate unsteady flamelets and obtained by tracing
Eulerian particles. The probability density of particles is obtained by solving a
passive scalar transport equation for each particle.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Publisher
© Anand OdedraPublication date
2007Notes
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.497217Language
- en