Enright, Ryan

Frijns, AJH Arjan

Nedea, SV Silvia

Wolf, MCW Moritz

Repository TU/e

Molecular water layer evaporation &amp; condensation

Wolf, M.C.W.

Frijns, A.J.H.

Gaastra - Nedea, S.V.

Pure OAI Repository

 Molecular water layer evaporation & condensationCitation for published version (APA):Wolf, M. C. W., Frijns, A. J. H., Gaastra - Nedea, S. V., & Enright, R. (2017). Molecular water layer evaporation &condensation. In Proceedings of the 2nd MIGRATE Workshop, June 29-30, 2017, Sofia, Bulgaria (pp. 47-48).Article 154795.Document status and date:Published: 29/06/2017Document Version:Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the version of the article upon submission and before peer-review. There can beimportant differences between the submitted version and the official published version of record. Peopleinterested in the research are advised to contact the author for the final version of the publication, or visit theDOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and pagenumbers.Link to publicationGeneral rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            • Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            • You may not further distribute the material or use it for any profit-making activity or commercial gain            • You may freely distribute the URL identifying the publication in the public portal.If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, pleasefollow below link for the End User Agreement:www.tue.nl/taverneTake down policyIf you believe that this document breaches copyright please contact us at:openaccess@tue.nlproviding details and we will investigate your claim.Download date: 04. Oct. 2023Proceedings of the 2nd MIGRATE Workshop June 29-30, 2017 – Sofia, BulgariaMIGRATE2017:154795MOLECULAR WATER LAYER EVAPORATION & CONDENSATIONM.C.W. Wolf *1,2,  A.J.H. Frijns 2, S.V. Nedea 2, Ryan Enright 11Nokia Bell Labs, Blanchardstown Business & Technology Park Dublin, D15 Y6NT Ireland2 Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven, the NetherlandsKEY WORDSMolecular dynamics, nanopore evaporation, two-phase coolingABSTRACTThe past decade has seen a considerable growth in portable devices with mobile connectivity. Thisgrowth has been enabled by the development of high capacity telecommunication networks globally.Individuals require high data transfer capabilities to remotely stream large information sets (i.e. HDvideo) and this is leading to greater demands for next generation networks (i.e. 5G). To ensure thisgrowth  continues,  hardware  devices  must  be  smaller,  more  energy-efficient  and  provide  greaterfunctionality.  This  requirement  poses  a  thermal  management  challenge,  increasing  heat  transferdensity significantly. Novel materials and cooling methods, which are engineered at the micro- andnanoscale, are necessary to address this.The overall aim of this project is to examine and maximize the heat transfer performance capabilitiesin an enclosed two-phase micro-system architecture. Figure 1: Nanopore evaporationA very promising cooling technique for the increasing heat transfer density is the method depicted inFig.  1. In this two-phase cooling system, the liquid phase evaporates from the nanopores to the gasphase [1]. The latent heat of vaporization is the dominant mode of heat transfer while the nanoporegeometry generates the requisite capillary pressure to drive the liquid flow to the heat source. This willbe studied numerically (to increase the fundamental understanding of the phenomena) and be used toinform detailed experiments and system level design. Therefore, various solids (Si, SiO2,...), gases (Ar,H2O, N2,..) and rarefaction levels will be studied numerically.In order to study the two-phase cooling system, we start with a simplified model of evaporation andcondensation of a water layer system as shown in Fig. 2. We use Molecular Dynamics to investigatedifferent properties of the simulation such as the temperature profile, heat flux, velocity distribution,water molecule orientation (WMO) [4] and the density distribution.1* Corresponding authorA Marie-Curie-ITN within H202047 sciencesconf.org:migrate2017:154795Proceedings of the 2nd MIGRATE Workshop June 29-30, 2017 – Sofia, BulgariaThe dimensions of the simulation model are Lx, Ly = 121 Å, Lz = 260 Å and Lpt = 200 Å. The temperature at the bottom and topwalls  are  kept  constant  using  a  Nose-Hoover  thermostat  withT1=368K and T2=278K. Periodic boundary conditions are appliedin x,y and z direction. The water molecules are modeled using theTIP4P/2005 model [2] and the interaction between the 8 layers ofplatinum atoms are modeled using harmonic springs [3].The results obtained so far are the WMO and the density distribution. It is observed in Fig. 3 that thereexists a preferred water molecule orientation around 80°-120° and 40° near the bottom wall. A similar observation can be made near the upper wall. In the bulk no preferred WMO is observed. This couldinfluence the liquid-vapor interface and evaporation.  The density distribution along the z-axis shownin Fig. 4 indicates the high density in the wallsand a decay near the liquid vapor interface.The  temperature  profile,  which  is  underinvestigation at  the  moment,  will  give us  theopportunity to see possible temperature jumpsnear  the  solid-liquid  and/or  liquid/vaporinterface  and  thereby  provide  us  detailedinformation on the evaporation resistances.AcknowledgementsThis project has received funding from the European Union’s Horizon 2020 research and innovationprogramme under the Marie Skłodowska-Curie grant agreement No. 643095. References and Citations[1] D.F.  Hanks  (2016).  Evaporation  from  Nanoporous  Membranes  for  High  Heat  Flux  ThermalManagement. PhD thesis, MIT[2] Orsi, M. (2014). Comparative assessment of the ELBA coarse-grained model for water. MolecularPhysics, 112(11), 1566-1576.[3] D.Torri  and T.Ohara (2007).  Molecular dynamics study on ultrathin liquid water film shearedbetween platinum solid walls: Liquid structure and energy and momentum transfer. J. Chem. Phys, 126(15):154706.[4] J.  Kim  (2014).  Molecular  Models  for  Water  Vapor  Flows  in  Silica  Nanopores.  PhD  thesis,Eindhoven University of TechnologyA Marie-Curie-ITN within H2020Figure 4: Density distribution along the z-axis. Red linesindicate the wallsFigure  3: WMO near the bottom wall. Red line:  begin of the bottomwall. Right insert: definition of water molecule orientation (WMO).Figure  2: Simulation  model  forevaporation and condensation of awater layer48 sciencesconf.org:migrate2017:154795

English

 Molecular water layer evaporation & condensationCitation for published version (APA):Wolf, M. C. W., Frijns, A. J. H., Gaastra - Nedea, S. V., & Enright, R. (2017). Molecular water layer evaporation &condensation. In Proceedings of the 2nd MIGRATE Workshop, June 29-30, 2017, Sofia, Bulgaria (pp. 47-48).Article 154795.Document status and date:Published: 29/06/2017Document Version:Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the version of the article upon submission and before peer-review. There can beimportant differences between the submitted version and the official published version of record. Peopleinterested in the research are advised to contact the author for the final version of the publication, or visit theDOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and pagenumbers.Link to publicationGeneral rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            • Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            • You may not further distribute the material or use it for any profit-making activity or commercial gain            • You may freely distribute the URL identifying the publication in the public portal.If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, pleasefollow below link for the End User Agreement:www.tue.nl/taverneTake down policyIf you believe that this document breaches copyright please contact us at:openaccess@tue.nlproviding details and we will investigate your claim.Download date: 17. Nov. 2023Proceedings of the 2nd MIGRATE Workshop June 29-30, 2017 – Sofia, BulgariaMIGRATE2017:154795MOLECULAR WATER LAYER EVAPORATION & CONDENSATIONM.C.W. Wolf *1,2,  A.J.H. Frijns 2, S.V. Nedea 2, Ryan Enright 11Nokia Bell Labs, Blanchardstown Business & Technology Park Dublin, D15 Y6NT Ireland2 Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven, the NetherlandsKEY WORDSMolecular dynamics, nanopore evaporation, two-phase coolingABSTRACTThe past decade has seen a considerable growth in portable devices with mobile connectivity. Thisgrowth has been enabled by the development of high capacity telecommunication networks globally.Individuals require high data transfer capabilities to remotely stream large information sets (i.e. HDvideo) and this is leading to greater demands for next generation networks (i.e. 5G). To ensure thisgrowth  continues,  hardware  devices  must  be  smaller,  more  energy-efficient  and  provide  greaterfunctionality.  This  requirement  poses  a  thermal  management  challenge,  increasing  heat  transferdensity significantly. Novel materials and cooling methods, which are engineered at the micro- andnanoscale, are necessary to address this.The overall aim of this project is to examine and maximize the heat transfer performance capabilitiesin an enclosed two-phase micro-system architecture. Figure 1: Nanopore evaporationA very promising cooling technique for the increasing heat transfer density is the method depicted inFig.  1. In this two-phase cooling system, the liquid phase evaporates from the nanopores to the gasphase [1]. The latent heat of vaporization is the dominant mode of heat transfer while the nanoporegeometry generates the requisite capillary pressure to drive the liquid flow to the heat source. This willbe studied numerically (to increase the fundamental understanding of the phenomena) and be used toinform detailed experiments and system level design. Therefore, various solids (Si, SiO2,...), gases (Ar,H2O, N2,..) and rarefaction levels will be studied numerically.In order to study the two-phase cooling system, we start with a simplified model of evaporation andcondensation of a water layer system as shown in Fig. 2. We use Molecular Dynamics to investigatedifferent properties of the simulation such as the temperature profile, heat flux, velocity distribution,water molecule orientation (WMO) [4] and the density distribution.1* Corresponding authorA Marie-Curie-ITN within H202047 sciencesconf.org:migrate2017:154795Proceedings of the 2nd MIGRATE Workshop June 29-30, 2017 – Sofia, BulgariaThe dimensions of the simulation model are Lx, Ly = 121 Å, Lz = 260 Å and Lpt = 200 Å. The temperature at the bottom and topwalls  are  kept  constant  using  a  Nose-Hoover  thermostat  withT1=368K and T2=278K. Periodic boundary conditions are appliedin x,y and z direction. The water molecules are modeled using theTIP4P/2005 model [2] and the interaction between the 8 layers ofplatinum atoms are modeled using harmonic springs [3].The results obtained so far are the WMO and the density distribution. It is observed in Fig. 3 that thereexists a preferred water molecule orientation around 80°-120° and 40° near the bottom wall. A similar observation can be made near the upper wall. In the bulk no preferred WMO is observed. This couldinfluence the liquid-vapor interface and evaporation.  The density distribution along the z-axis shownin Fig. 4 indicates the high density in the wallsand a decay near the liquid vapor interface.The  temperature  profile,  which  is  underinvestigation at  the  moment,  will  give us  theopportunity to see possible temperature jumpsnear  the  solid-liquid  and/or  liquid/vaporinterface  and  thereby  provide  us  detailedinformation on the evaporation resistances.AcknowledgementsThis project has received funding from the European Union’s Horizon 2020 research and innovationprogramme under the Marie Skłodowska-Curie grant agreement No. 643095. References and Citations[1] D.F.  Hanks  (2016).  Evaporation  from  Nanoporous  Membranes  for  High  Heat  Flux  ThermalManagement. PhD thesis, MIT[2] Orsi, M. (2014). Comparative assessment of the ELBA coarse-grained model for water. MolecularPhysics, 112(11), 1566-1576.[3] D.Torri  and T.Ohara (2007).  Molecular dynamics study on ultrathin liquid water film shearedbetween platinum solid walls: Liquid structure and energy and momentum transfer. J. Chem. Phys, 126(15):154706.[4] J.  Kim  (2014).  Molecular  Models  for  Water  Vapor  Flows  in  Silica  Nanopores.  PhD  thesis,Eindhoven University of TechnologyA Marie-Curie-ITN within H2020Figure 4: Density distribution along the z-axis. Red linesindicate the wallsFigure  3: WMO near the bottom wall. Red line:  begin of the bottomwall. Right insert: definition of water molecule orientation (WMO).Figure  2: Simulation  model  forevaporation and condensation of awater layer48 sciencesconf.org:migrate2017:154795

https://pure.tue.nl/ws/files/101465357/Wolf_migrate2017_en.pdf

Molecular water layer evaporation & condensation

Abstract

Similar works

Full text

Available Versions

Repository TU/e

Pure OAI Repository

Pure OAI Repository

Molecular water layer evaporation &amp; condensation

Abstract

Similar works

Full text

Available Versions

Repository TU/e

Pure OAI Repository

Pure OAI Repository

Molecular water layer evaporation & condensation