Master of Science in Mechanical Engineering (MSME)
Magnetic field effects in combustion is an area of study that has previously been overlooked. The influence of magnetic fields on flames has only recently been explored and is of interest both from a scientific and a practical standpoint. This study provides theoretical, numerical and experimental evidence that combustion can be affected with the use of suitable magnetic fields. This thesis focuses on four different types of magnetic field: homogeneous, gradient, oscillating and pre-combustion. For the homogeneous field case, the Gibbs Free Energy method was used to determine the mole fraction of product species. It was found that homogeneous fields have negligible effects on combustion characteristics. Different magnetic gradient configurations were then tested using Finite Element Methods to obtain the force field profile on paramagnetic oxygen. Numerical simulations showed that high magnetic field gradients at high magnetic strengths, such as those exerted by spherical permanent magnets, are most suitable to enhance oxygen entrainment into a reaction zone. Also, from experimental data, it was shown that the concentration of oxygen around a diffusion flame has a higher increase if the momentum of the flame jet exit is low. Furthermore, a digital imagery study quantitatively demonstrated that soot particle agglomeration is decreased with the use of gradient magnetic fields. Experimentations with oscillating magnetic fields confirmed that an alternating magnetic field produces a varying force field around a diffusion flame, which enhances mixing between fuel and oxidizer. Finally, pre-combustion magnetic fields increased the temperature on the lower portion of a diffusion flame suggesting possible dissociation of the fuel molecules resulting in more complete combustion.
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Gonzalez, Diego F., "Magnetic field effects on diffusion flames" (2008). LSU Master's Theses. 2936.