Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers

dc.contributor.authorEbeling, Christopher P.en
dc.contributor.committeechairThole, Karen A.en
dc.contributor.committeememberVick, Brian L.en
dc.contributor.committeememberTafti, Danesh K.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2011-08-06T16:06:44Zen
dc.date.adate2003-06-25en
dc.date.available2011-08-06T16:06:44Zen
dc.date.issued2003-07-23en
dc.date.rdate2004-06-25en
dc.date.sdate2003-06-23en
dc.description.abstractCompact heat exchangers are usually characterized by a large heat transfer surface per unit of volume. These characteristics are useful when thermal energy between two or more fluids must be exchanged without mixing. Most compact heat exchangers are liquid-to-air heat exchangers, with approximately 85% of the total thermal resistance occurring on the air side of the heat exchanger. To reduce the space and weight of a compact heat exchanger, augmentation strategies must be proposed to reduce the air side resistance. However, before any strategies to augment the air side heat transfer can be proposed, a thorough insight of the current mechanisms that govern air side heat transfer is required. The tube wall heat transfer results presented in this paper were obtained both experimentally and computationally for a typical compact heat exchanger design. Both isothermal and constant heat flux tube walls were studied. For the experimental investigation, a scaled-up model of the louvered fin-tube wall was tested in a flow facility. Although computational results for the isothermal tube wall are shown, control of the experimental isothermal tube wall proved to be unrealistic and only heat transfer measurements along the constant heat flux tube wall were made. For the constant heat flux tube wall, reasonable agreement has been achieved between the measurements and the steady, three-dimensional computational predictions. The results of the study showed that high heat transfer coefficients existed at the entrance to the louver array as well as in the louver reversal region. Vortices created at the leading edge of the louvers augmented heat transfer by thinning the tube wall boundary layer. Results indicate that an augmentation ratio of up to 3 times can occur for a tube wall of a louvered fin compact heat exchanger as compared to a flat plate.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.otheretd-06232003-172030en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06232003-172030en
dc.identifier.urihttp://hdl.handle.net/10919/10140en
dc.publisherVirginia Techen
dc.relation.haspartEbeling_thesis2.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCompact heat exchangeren
dc.subjectLouvered finsen
dc.subjectTube wallen
dc.titleMeasurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangersen
dc.typeThesisen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen
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