Full Content is available to subscribers

Subscribe/Learn More  >

Significant Heat Transfer Enhancement in Microchannels With a Segmented Flow of Two Immiscible Liquids

[+] Author Affiliations
Ashish Asthana, Igor Zinovik, Christian Weinmueller, Dimos Poulikakos

ETH Zurich, Zurich, Switzerland

Paper No. IHTC14-22830, pp. 141-149; 9 pages
  • 2010 14th International Heat Transfer Conference
  • 2010 14th International Heat Transfer Conference, Volume 6
  • Washington, DC, USA, August 8–13, 2010
  • Conference Sponsors: Heat Transfer Division
  • ISBN: 978-0-7918-4941-5 | eISBN: 978-0-7918-3879-2
  • Copyright © 2010 by ASME


With the advancement in microfabrication technologies the size of electronic devises keeps decreasing. At the same time high density of circuits and the directly related heat generation requires simultaneous increase in the performance of cooling systems to keep the electronics operating at optimum temperatures. Liquid cooling incorporating microchannel networks as the heat sinks is known to be a promising approach to this heat transfer problem because of its plausible manufacturability at the chip level. However, even the upper range of heat fluxes achieved in such microchannel heat sinks will not meet the increasing demands of the electronics industry. We present herein a novel experimental study of convective heat transfer in serpentine microchannels with segmented liquid-liquid emulsions. It is demonstrated that this concept yields significant heat transfer enhancement in micro channel heat sinks compared to traditional single phase liquid cooling. The flow of water and mineral oil droplets is examined experimentally in microchannels with cross section 100 by 100 μm and flow rates up to 130 μl/min. The study is focused on the investigation of the local temperature of the liquid and on the influence of the oil droplets on the temperature distribution and heat transfer. Laser Induced Fluorescence (LIF) is employed to measure the temperature of the flow fields with and without droplets, and PIV measurements are conducted to determine the velocity field. The range of flow conditions which led to a stable segmented flow with enhancement of heat transport was identified. The increase of the oil fraction was accompanied by an increase of the recirculation zone in the transverse direction to the flow and by higher velocity gradients inside the zones thus resulting in enhanced mixing of water across the channel. The LIF measurements indicate that for the same total flow rate, the local temperature of the water region separating the droplets will be higher than in the case of single phase liquid flow. For segmented flow, up to a four-fold increase of the Nusselt number compared to pure water flow was observed.

Copyright © 2010 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In