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Mechanical Engineering Seminar Static and
Dynamic Stability of Bluff-body Stabilized Premixed Flames Baki M. Cetegen,
Ph.D. Mechanical
Engineering Department University
of Connecticut, Storrs, CT Abstract Stability
characteristics (blowoff, flashback and flame response to flow oscillations)
are important considerations in the design and operation of highly energetic
combustion devices such as gas turbine combustors, afterburners, furnaces and
rockets. Of particular interest is
the flame behavior under fuel lean combustion conditions since many pollution
reduction schemes are based on fuel lean combustion. Under such conditions, flames are susceptible to external
perturbations and they can detach from flame holders and extinguish. In this presentation, a detailed
experimental study of bluff-body stabilized premixed flames will be described
in three parts. In the first part,
the flame blow-off conditions will be characterized for steady and periodic
flow conditions upstream of the flame.
These results will be interpreted in the context of detailed
measurements of velocities and flame front strain rates in the flame holder
wake region utilizing particle image velocimetry. In the second part, results from ongoing experiments with
imposed fuel-air mixture gradients upstream of the flame holder will be
described. Finally, the spectroscopic temperature measurements in the
bluff-body flame stabilization zone will be presented to help in understanding
of the flame blow-off characteristics under different conditions. Tuesday,
November 6, 2007, 10:30 am
3540
Engineering
Refreshments
served at 10:15 am
Biography Prof.
Cetegen received his B.S. ME degree with minor in Physics (1978) from Bosphorus
University in Istanbul Turkey. He
obtained his M.S. ME (1979) from UC, Berkeley followed by his Ph.D. in ME
(1982) from Caltech. After working
at Energy and Environmental Research Corporation for five years, and a brief
stint as a post doctoral fellow at UC, Irvine, he joined University of
Connecticut faculty in 1987 where he is currently serves as professor and
department head of Mechanical Engineering. His research has spanned topics such as fluid mechanics of
buoyant plumes and flames, detonations, combustion and plasma synthesis of
ceramics and ceramic coatings, experimental studies of vortical mixing and
vortex-combustion interactions, optical diagnostics for combustion systems and
fuel cells. He is a fellow of ASME
and serves on the executive board of the Eastern States Section of the
Combustion Institute as its treasurer. |