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dc.contributor.advisorGang Chen.en_US
dc.contributor.authorWang, Jianjian, Ph. D. Massachusetts Institute of Technologyen_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Mechanical Engineering.en_US
dc.date.accessioned2011-08-18T19:17:56Z
dc.date.available2011-08-18T19:17:56Z
dc.date.copyright2011en_US
dc.date.issued2011en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/65318
dc.descriptionThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (p. 82-89).en_US
dc.description.abstractOver the past decade, some groups have reported that nanofluids, which are liquids containing suspensions of nanoparticles, have substantially higher thermal conductivity than that of the base fluids. However, the reported high thermal conductivity sometimes cannot be reproduced. Theoretically, potential mechanisms leading to this enhancement are still under scrutiny. In this thesis, we present experimental studies aiming at understanding heat conduction mechanisms in nanofluids. We use graphite flakes as additives and developed methods to prepare stable graphite suspensions. The thermal conductivity enhancement of our suspensions achieved record high thermal conductivity values in different base fluids including water, engine oil, and ethylene glycol. This thesis investigates the effect of graphite flake preparation methods such as microwave and ultrasonic on the thermal conductivity of the suspensions, and found that graphite flakes of tens of nanometer in thickness but tens of microns in size lead to higher thermal conductivity values. To better understand the transport mechanisms, the electrical properties of graphite suspensions are also investigated using AC impedance spectroscopy. The AC impedance spectroscopy leads to insights on how the internal structures of the flake clusters affect heat conduction. Based on the experimental studies, we conclude that the thermal conductivity enhancement in these suspensions is due to percolation heat conduction along graphite flakes.en_US
dc.description.statementofresponsibilityby Jianjian Wang.en_US
dc.format.extent89 p.en_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectMechanical Engineering.en_US
dc.titleInvestigation on thermal conductivity and AC impedance of graphite suspensionen_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Mechanical Engineering.en_US
dc.identifier.oclc745803791en_US


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