Identifier

etd-04022014-023542

Semester of Graduation

May 2014

Degree

Master of Science in Mechanical Engineering (MSME)

Department

Mechanical Engineering

Document Type

Thesis

Abstract

The reliance on combustion as the primary source of energy will continue in the US for the next thirty years [1]. Experiments suggest that the use of magnetic fields can be one tool in the many-sided approach to the problem of environmental protection and energy conservation in the US. For instance, it is estimated that an increase in efficiency of 2% in spray combustion can save the US economy billions of dollars [2]. In this thesis I report on improving the quality of combustion through the use of magnetic fields. (1)I investigated the effects of magnetic fields on the evaporation and burning of a single droplet by deriving and solving the conservation equations for a droplet injected into a gas with an initial velocity. Some enhancements reported include temperature-dependent thermophysical properties, the concept of thermal layer for considering a nonuniform temperature within the droplet, and modeling of the Stefan flow at the interface as a binary mixture. The results presented support the statement that a reduction of droplet lifetime of 35% or more is feasible using magnetic fields of the order of one tesla. (2)I also studied configurations of single magnets and pair of identical magnets to quantify the convective effects and the attractive force on oxygen produced by magnetic fields, which enhance the processes that sustain a flame and promote evaporation. By solving Maxwell’s equations and performing optimization, a relation between the position of the flame (or droplet) and the shape or size of the magnet was obtained. For single permanent magnets the results indicate that the optimum radius for a spherical magnet equals six times the separation of the flame (or droplet) from the magnet. Analogously for a single cone the optimum shape is given by radius/height equal to 1.5. For pairs of identical magnets the method of superposition of magnetic dipoles allowed ranking configurations. The results presented show, for instance, that for a separation between the magnets of 3 cm and a size of 125 cm3 (per magnet) cylindrical magnets with radius/height equal to 0.5 ranks first.

Date

2014

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Charalampopoulos, Tryfon T

DOI

10.31390/gradschool_theses.365

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