Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"jumping-droplet"”.
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Enhanced coalescence-induced jumping droplet departure
… in recent years due to its ability to shed water droplets at length scales three decades smaller than the capillary length (~ 1mm) via coalescence induced droplet jumping. Jumping-droplet condensation has been demonstrated to enhance heat transfer, anti-icing, and self-cleaning efficiency, and is …
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A comprehensive model of electric-field-enhanced jumping-droplet condensation on superhydrophobic surfaces
… performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the capillary length, and allowing the use of external electric fields to enhance droplet removal and heat transfer, in what has been termed electric-field-enhanced (EFE) …
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Evaporative cooling via jumping droplet condensation on superhydrophobic surfaces for localized car air conditioning
… to these problems uses evaporative cooling via jumping droplet condensation on superhydrophobic surfaces to provide localized cooling with 100 times less power input. Jumping droplet condensation takes place when microscale droplets coalesce on superhydrophobic surfaces and excess surface energy …
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Developing an active, high-heat-flux thermal management strategy for power electronics via jumping-droplet phase-change cooling
… electronics via electric-field-enhanced (EFE) jumping-droplet condensation. To test the viability of EFE condensation for electronic hot spot cooling, an experimental setup was developed to remove heat via droplet evaporation from single and multiple high-power gallium nitride (GaN) transistors …
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Electrowetting study of jumping droplets on hydrophobic surfaces
Recent studies have shown that jumping-droplet-enhanced condensation has higher heat transfer than state-of-the-art dropwise condensing surfaces by -30-40%. Jumping-droplet condensation occurs due to the conversion of surface energy to kinetic energy during the coalescence of microscale droplets, …
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Liquid-vapor phase change phenomena for heat exchangers and electronics cooling
… power generation, and water desalination. Jumping-droplet condensation of water has recently been shown to have a 10X heat transfer enhancement compared to state-of-the-art filmwise condensation due to the removal of condensate at much smaller length scales (~ 1µm) than what is capable with …
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Design and fabrication of an internal condensation loop for effectiveness and robustness testing of nanostructured superhydrophobic steam condenser
… causes condensation to instead occur via the jumping droplet mechanism, which promises drastically improved heat exchanging performance. This thesis discusses the design and fabrication of an internal condensation loop which will allow us to test the heat transfer, fluid dynamic performance of …
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Exploiting Interfacial Phenomena to Expel Matter from its Substrate
… to be fully understood. Even though we know how jumping-droplet condensation offers significantly better heat transfer performance than regular dropwise condensation and can liberate foreign particles, fundamental questions on the effect of surface orientation on jumping-droplet condensation or …
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Heat transfer through a condensate droplet on hydrophobic and nanostructured superhydrophobic surfaces
… In this thesis, we reconcile classical droplet growth modeling barriers by utilizing two-dimensional axisymmetric numerical simulations to study individual droplet heat transfer on non-wetting surfaces (90° < θ_a < 170°). Incorporation of an appropriate convective boundary condition at …
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Natural and engineered surfaces for enhanced phase change heat transfer
… sytems by leveraging thin film condensation and jumping-droplet induced localized hot spot cooling.
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Electrostatic charging of jumping droplets on superhydrophobic nanostructured surfaces : fundamental study and applications
… condensation heat transfer, where the low droplet surface adhesion and small droplet departure sizes increase the condensation heat transfer coefficient. Specifically, when two or more small (~10-100 [mu]m) droplets coalesce on a superhydrophobic surface, they can spontaneously jump away …
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Enhanced phase change heat transfer through advanced fabrication techniques
… researchers have observed that when microdroplets (~10 – 100 μm) condense and coalesce on an ultra-low adhesion structured surface, the resulting excess surface energy causes the droplet to jump out of the surface against gravity. The removal of coalesced condensate droplets leads to rapid …
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Fabrication and robustness testing of superhydrophobic nanostructured surfaces for enhanced jumping condensation
… and nano-structured surfaces which promote a jumping droplet mode of condensation have been shown to enhance heat transfer over conventional film wise condensation surfaces, but limited robustness testing has been reported validating feasibility of industrial implementation. This thesis seeks …
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Development and characterization of micro/nano structured surfaces for enhanced condensation
… heat transfer performance. We first studied droplet-surface interactions during condensation on superhydrophobic surfaces to understand the emergent droplet wetting morphology. We demonstrated the importance of considering local energy barriers to understand the condensed droplet morphologies …
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The Effects of Surface Topography on Droplet Evaporation and Condensation
Droplet evaporation and condensation are two important topics of interest, since these two phase-change phenomena not only occur in the cycle of global water, e.g., the formation of rain, fog, dew, and snow in nature, but also play a critical role in a variety of applications including phase-change …
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Coalescence-induced nanodroplet jumping
Made available in DSpace on 2016-07-07T20:35:12Z (GMT). No. of bitstreams: 2 CHA-THESIS-2016.pdf: 2224018 bytes, checksum: 497c21f5ec14cea688f8b206e81b1b44 (MD5) LICENSE.txt: 4210 bytes, checksum: b076c2ca76ed752c030fdb8c95f208df (MD5) Previous issue date: 2016-04-28
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Condensation driven solid-liquid interfacial phenomenon on functional surfaces
Made available in DSpace on 2020-08-27T00:49:55Z (GMT). No. of bitstreams: 3 CHA-DISSERTATION-2020.pdf: 9393430 bytes, checksum: bad2af1456c79eca3ecc06813874b9f7 (MD5) LICENSE.txt: 4210 bytes, checksum: 158c48014e3d7208a4aed33c3343a6cc (MD5) PROQUEST_LICENSE.txt: 4556 bytes, checksum: …
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Surface micro/nano structuring and functionalization for phase change heat transfer enhancement
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-05-01