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Title page for etd-0125106-162129


URN etd-0125106-162129 Statistics This thesis had been viewed 3391 times. Download 2493 times.
Author Chi-Yuan Lai
Author's Email Address cyla@ms27.hinet.net
Department Mechanical Engineering
Year 2005 Semester 1
Degree Ph.D. Type of Document Doctoral Dissertation
Language English Page Count 140
Title Longitudinal and Annular Fin Analysis with Variable Thermal Properties by Recursive Formulation and Optimum Design of a Heat Sink
Keyword
  • thermal properties
  • optimum
  • heat sink
  • fin
  • fin
  • heat sink
  • optimum
  • thermal properties
  • Abstract The first two topics in this study supply a new approach to calculate thermal performance of a singular longitudinal fin and annular fin with variable thermal properties. With discrete model, the singular fin can be divided into many sections. Then, each section can be combined together to obtain the whole solution of the fin by recursive numerical formulation. The recursive formulas for both conditions with and without heat transfer on fin tip are derived in the present study. Finally, several examples including composite and boiling mode of a fin have been simulated to demonstrate the validity of the present approach.
    Later the theoretical analysis of the cooling effect of a heat sink is presented. With the input data of Biot number, Bi, heat transfer coefficient ratios, H and H*, the optimum heat transfer equation can be utilized to obtain the optimum length of fins in a longitudinal fin heat sink that affects the overall thermal effectiveness of a heat sink. This optimum equation is in transcendental form, which involves three dimensionless parameters. The thermal resistance of a heat sink is derived and examples are provided to illustrate the effect on the cooling performance of a heat sink under various design conditions. Subject to annular fin heat sink, the four parameters are found to provide the optimum equation in transcendental form. Heat sink performance with its various parameters is also discussed in this topic. This optimum equation can be utilized to find the optimum outer radius of annular fins and fin number on a heat sink that affects the overall thermal effectiveness of a heat sink. Finally, examples are offered to illustrate the cooling performance of a heat sink including annular fins.
    Advisor Committee
  • Hong-Sen Kou - advisor
  • Ji-Jen Lee - advisor
  • none - co-chair
  • Rong-Hua Yeh - co-chair
  • Sheam-Chyun Lin - co-chair
  • Shih-Pin Liaw - co-chair
  • Tong-Miin Liou - co-chair
  • Files indicate access worldwide
    Date of Defense 2006-01-13 Date of Submission 2006-01-25


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