Phase change has long been known to be an efficient method of heat transfer, due to the latent energy released at constant or near-constant temperature. Pool boiling in particular has been previously used to remove heat fluxes in excess of 1 MW/m2. As technological advances continue to reduce the footprint of high power devices it is critical to investigate boiling heat transfer processes on the nanoscale, so that more efficient heat flux removal can be achieved. In the present work molecular dynamics (MD) is used to simulate various pool boiling scenarios in order to gain a better understanding of the critical factors affecting nanoscale heat transfer. In the first study the effect of hetero- and homogeneous wettability on nanostructured substrates is investigated to understand evaporation and heat flux characteristics. Results reveal that the substrates modified with hydrophilic nano-posts produce larger heat fluxes than heterogenous nanostructure/base wall combinations, due to enhanced kinetic energy transfer. A new coordination number criterion for liquid argon is developed to aid in tracking vapor atoms. The second study details the effect of contact angle and nanostructure pitch on maximum heat flux. Heat flux is found to increase with increasing pitch and decreasing contact angle, reaching an overall maximum of 159 MW/m2. For larger pitches the superheat at which the peak heat flux occurs increases with both contact angle and pitch. In the final study single-layer graphene (SLG) topped substrates were simulated in the pool boiling of water. Results show improvements over plain substrates of 2-10x in heat flux values, which are on the order of 10 MW/m2. CHF was also found to increase by as much as 14% with the addition of SLG, with lower superheats required to attain the CHF condition.
Subject (authority = RUETD)
Topic
Mechanical and Aerospace Engineering
RelatedItem (type = host)
TitleInfo
Title
Rutgers University Electronic Theses and Dissertations
Identifier (type = RULIB)
ETD
Identifier
ETD_8864
PhysicalDescription
Form (authority = gmd)
electronic resource
InternetMediaType
application/pdf
InternetMediaType
text/xml
Extent
1 online resource (xii, 151 p. : ill.)
Note (type = degree)
Ph.D.
Note (type = bibliography)
Includes bibliographical references
Subject (authority = ETD-LCSH)
Topic
Molecular dynamics
Note (type = statement of responsibility)
by Ricardo Diaz
RelatedItem (type = host)
TitleInfo
Title
School of Graduate Studies Electronic Theses and Dissertations
Identifier (type = local)
rucore10001600001
Location
PhysicalLocation (authority = marcorg); (displayLabel = Rutgers, The State University of New Jersey)
I hereby grant to the Rutgers University Libraries and to my school the non-exclusive right to archive, reproduce and distribute my thesis or dissertation, in whole or in part, and/or my abstract, in whole or in part, in and from an electronic format, subject to the release date subsequently stipulated in this submittal form and approved by my school. I represent and stipulate that the thesis or dissertation and its abstract are my original work, that they do not infringe or violate any rights of others, and that I make these grants as the sole owner of the rights to my thesis or dissertation and its abstract. I represent that I have obtained written permissions, when necessary, from the owner(s) of each third party copyrighted matter to be included in my thesis or dissertation and will supply copies of such upon request by my school. I acknowledge that RU ETD and my school will not distribute my thesis or dissertation or its abstract if, in their reasonable judgment, they believe all such rights have not been secured. I acknowledge that I retain ownership rights to the copyright of my work. I also retain the right to use all or part of this thesis or dissertation in future works, such as articles or books.