Temperature Measurements of Laminar Diffusion Flames
in Non-Uniform Magnetic Fields Using Holographic Interferometry
Rajani K. Varagani, Jonathan W. Woolley, John Baker, and Kozo Saito
Combustion and Flame
Status: In Submission, submitted April 16, 2009
ABSTRACT
The behavior of laminar slot diffusion flames in the
presence of non-uniform upward decreasing magnetic fields was investigated.
Effect of non-uniform magnetic fields on flame height, flame shape, and the
temperature distribution in the vicinity of the flames were studied. Propane,
butane, and methane gases have been used as fuels. The magnetic fields were produced
by a magnet assembly consisting of neodymium iron boron permanent magnets and
gray steel prisms. The peak magnetic fields considered here were 0.95 T, 0.85
T, and 0.75 T. The flow rates examined in these fields were 35, 40, 45, and 50
sccm using a burner port of width 0.22 mm and length 32mm.Diffusion flames are influenced by the
magnetic fields because the constituent gases are diamagnetic and paramagnetic
in nature.Holographic interferometry
was used to obtain qualitative temperature distributions in the vicinity of the
flames. Different regimes such as buoyancy-controlled, momentum-controlled, and
magnetically-controlled regimes were identified by using various previously
defined dimensionless parameters. The experimental data expressed in terms of
grouped dimensionless parameters were found to exhibit universal behavior. By
the application of non-uniform magnetic fields, it was observed that under
certain conditions the temperature decreases, flame length decreases, and flames
become smaller in size.
