Menu 
  • Home
  • Research on Station
        • Benefits of Research on the ISS
        • Industrial R&D
        • Current Project Pipeline
        • Researcher Interviews
      • Current RFI

        hardware

        RFI-Organs-On-Chips Research

      • Researcher Interviews

        No items found
  • Getting to Space
        • Getting to Space
        • Implementation Partners
        • ISS Hardware
        • Proposal Submission Process
        • Launch Vehicles
        • Support Services
      • Recent Posts

        No items found
      • Projects in Flight

        • GLASS AIS TransponderGlobal AIS on Space Station (GLASS)
        • MultiLab: Research Server for the ISS
        • Story Time from Space – 2
        • NIH-Osteo
        • Materials Testing: The Evaluation of Gumstix Modules in Low Earth Orbit
        View Current ISS Project Pipeline »
  • Research Library
        • ISS National Lab Research Database
        • ISS National Lab Reports
        • Web Resources
        • Research Apps
      • Recently Added Research

        • Genotype, B-vitamin status, and androgens affect spaceflight-induced ophthalmic changes
        • SUBSONIC MOTION OF A PROJECTILE IN A FLUID COMPLEX PLASMA UNDER MICROGRAVITY CONDITIONS
        • Coactivator-Dependent Oscillation of Chromatin Accessibility Dictates Circadian Gene Amplitude via REV-ERB Loading
      • Popular Tags

        • Cell Differentiation
        • Earth Observation
        • Fluid physics
        • Gene Expression
        • Human Research
        • Material science
        • Mice
        • Microbiology
        • Simulated microgravity
        • Technology demonstration
  • Make Contact
  • Home
  • Research on Station
    • Benefits of Microgravity
    • Industrial R&D
    • Current Project Pipeline
    • Research Opportunities
    • Researcher Interviews
  • Facilities & Hardware
    • ISS Hardware
    • Implementation Partners
  • Getting to Space
    • Getting to Space
    • Proposal Submission Process
    • Launch Vehicles
  • Research Library
    • Research Apps
    • Researcher Guides
    • Resources
    • Publication Database

« Go Back

Thermocapillary Phenomena and Performance Limitations of a Wickless Heat Pipe in Microgravity

Kundan, Akshay, et al. (2015). "Thermocapillary Phenomena and Performance Limitations of a Wickless Heat Pipe in Microgravity." Physical Review Letters 114 14: 146105

A counterintuitive, thermocapillary-induced limit to heat- pipe performance was observed that is not predicted by current thermal-fluid models. Heat pipes operate under a number of physical constraints including the capillary, boiling, sonic, and entrainment limits that fundamentally affect their performance. Temperature gradients near the heated end may be high enough to generate significant Marangoni forces that oppose the return flow of liquid from the cold end. These forces are believed to exacerbate dry out conditions and force the capillary limit to be reached prematurely. Using a combination of image and thermal data from experiments conducted on the International Space Station with a transparent heat pipe, we show that in the presence of significant Marangoni forces, dry out is not the initial mechanism limiting performance, but that the physical cause is exactly the opposite behavior: flooding of the hot end with liquid. The observed effect is a consequence of the competition between capillary and Marangoni-induced forces. The temperature signature of flooding is virtually identical to dry out, making diagnosis difficult without direct visual observation of the vapor-liquid interface.

Related URLs:
http://link.aps.org/doi/10.1103/PhysRevLett.114.146105

ISSN: 1079-7114 (Electronic) 0031-9007 (Linking)

Accession Number: 25910141

Share this
0
0
0
Tags: Boiling, Capillary, Fluid behavior, Fluid physics, International Space Station, ISS, Temperature Gradients