Fabrication and characterization of nanostructured surfaces for enhanced heat transfer Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/kk91fp405

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • This objective of this study is to investigate the capability of nanostructured surfaces on dissipating heat flux by performing pool boiling and convective flow boiling. The generation of ultra-high heat flux from high performance electric devices has motivated a number of investigations related to advanced heat transfer especially in two-phase boiling performance. It has been reported by a number of researchers that nanostructured surfaces can result in much enhanced boiling performance, compared to the conventional methods by creating desire conditions for heat transfer. In this thesis, various nanostructured surfaces having different morphology were prepared on several engineering relevant substrates and were characterized for their pool boiling performance. Microreactor-assisted-nanomaterial-deposition, MAND™ was used to fabricate a variety of different ZnO nanostructured surfaces by careful adjustment of the processing parameters. ZSM-5 zeolite was synthesized using hydrothermal reaction. ZnO nanostructures in minichannel were also successfully deposited via a flow cell for the application of flow boiling experiment. Scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM) were carried out to characterize the micro- and nanostructures. Contact angle measurement was conducted to evaluate wettability and X-ray Diffraction (XRD) was used to determine the crystalline structures. The most significant enhancement of critical heat flux (CHF) and heat transfer coefficient (HTC) was observed in the flower like ZnO nanostructured surface. We observed pool boiling CHF of 80-82.5 W/cm² for nanostructured ZnO on Al surfaces versus a CHF of 23.2 W/cm² on a bare Al surface with a wall superheat reduction of 25-38°C. This new CHF values on nanostructured surfaces corresponds to a boiling heat transfer coefficient as high as ~ 23000 W/m²K. This represents an increase of almost 4X in CHF on nano-textured surfaces, which is the highest enhancement factor reported today.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Keyword
Subject
Rights Statement
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Laura Wilson(laura.wilson@oregonstate.edu) on 2009-11-09T18:38:31Z (GMT) No. of bitstreams: 1 ChoiChangho2010.pdf: 2753382 bytes, checksum: 133a8545ac39f8623b8f12188088a453 (MD5)
  • description.provenance : Approved for entry into archive by Julie Kurtz(julie.kurtz@oregonstate.edu) on 2009-11-05T18:24:48Z (GMT) No. of bitstreams: 1 ChoiChangho2010.pdf: 2753382 bytes, checksum: 133a8545ac39f8623b8f12188088a453 (MD5)
  • description.provenance : Submitted by Chang-Ho Choi (choic@onid.orst.edu) on 2009-11-02T20:15:14Z No. of bitstreams: 1 ChoiChangho2010.pdf: 2753382 bytes, checksum: 133a8545ac39f8623b8f12188088a453 (MD5)
  • description.provenance : Made available in DSpace on 2009-11-09T18:38:31Z (GMT). No. of bitstreams: 1 ChoiChangho2010.pdf: 2753382 bytes, checksum: 133a8545ac39f8623b8f12188088a453 (MD5)

Relationships

In Administrative Set:
Last modified: 08/14/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items