Research Papers

Orientation Effects in Two-Phase Microgap Flow

[+] Author and Article Information
Franklin L. Robinson

Thermal Engineering Branch
NASA Goddard Space Flight Center,
Greenbelt, MD 20771
e-mail: franklin.l.robinson@nasa.gov

Avram Bar-Cohen

Fellow ASME
Department of Mechanical Engineering,
University of Maryland,
College Park, MD 20742
e-mail: abc@umd.edu

Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the JOURNAL OF ELECTRONIC PACKAGING. Manuscript received January 22, 2019; final manuscript received April 7, 2019; published online May 17, 2019. Assoc. Editor: Ercan Dede. This work is in part a work of the U.S. Government. ASME disclaims all interest in the U.S. Government's contributions.

J. Electron. Packag 141(3), 031009 (May 17, 2019) (12 pages) Paper No: EP-19-1009; doi: 10.1115/1.4043483 History: Received January 22, 2019; Revised April 07, 2019

The high power density of emerging electronic devices is driving the transition from remote cooling, which relies on conduction and spreading, to embedded cooling, which extracts dissipated heat on-site. Two-phase microgap coolers employ the forced flow of dielectric fluids undergoing phase change in a heated channel within or between devices. Such coolers must work reliably in all orientations for a variety of applications (e.g., vehicle-based equipment), as well as in microgravity and high-g for aerospace applications, but the lack of acceptable models and correlations for orientation- and gravity-independent operation has limited their use. Reliable criteria for achieving orientation- and gravity-independent flow boiling would enable emerging systems to exploit this thermal management technique and streamline the technology development process. As a first step toward understanding the effect of gravity in two-phase microgap flow and transport, in the present effort the authors have studied the effect of evaporator orientation, mass flux, and heat flux on flow boiling of HFE7100 in a 1.01 mm tall × 13.0 mm wide × 12.7 mm long microgap channel. Orientation-independence, defined as achieving similar critical heat fluxes (CHFs), heat transfer coefficients (HTCs), and flow regimes across orientations, was achieved for mass fluxes of 400 kg/m2 s and greater (corresponding to a Froude number of about 0.8). The present results are compared to published criteria for achieving orientation- and gravity-independence.

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Bar-Cohen, A. , Robinson, F. L. , and Deisenroth, D. C. , 2018, “ Challenges and Opportunities in Gen3 Embedded Cooling With High-Quality Microgap Flow,” International Conference on Electronics Packaging and iMAPS All Asia Conference, Mie, Japan, Apr. 17–21.
Nakayama, W. , 2017, “ Evolution of Hardware Morphology of Large-Scale Computers and the Trend of Space Allocation for Thermal Management,” ASME J. Electron. Packag., 139(1), p. 010801. [CrossRef]
Brunschwiler, T. , Sridhar, A. , Ong, C. L. , and Schlottig, G. , 2016, “ Benchmarking Study of the Thermal Management Landscape for Three-Dimensional Integrated Circuits: From Back-Side to Volumetric Heat Removal,” ASME J. Electron. Packag., 138(1), p. 010911. [CrossRef]
Bar-Cohen, A. , 2014, “ Towards Embedded Cooling—Gen 3 Thermal Packaging Technology,” Encyclopedia of Thermal Packaging, World Scientific Publishing Company, Hackensack, NJ, pp. 367–398.
Bar-Cohen, A. , 2013, “ Gen-3 Thermal Management Technology: Role of Microchannels and Nanostructures in an Embedded Cooling Paradigm,” ASME J. Nanotech. Eng. Med., 4(2), p. 020907. [CrossRef]
Swanson, T. , and Motil, B. , 2015, “ NASA Technology Roadmaps TA 14: Thermal Management Systems,” National Aeronautics and Space Administration, Washington, DC, accessed Jan. 21, 2019, www.nasa.gov/sites/default/files/atoms/files/2015_nasa_technology_roadmaps_ta_14_thermal_management_final.pdf
Sunada, E. , Furst, B. , Bhandari, P. , Carroll, B. , Birur, G. C. , Nagai, H. , Daimaru, T. , Sakamoto, K. , Cappucci, S. , and Mizerak, J. , 2016, “ A Two-Phase Mechanically Pumped Fluid Loop for Thermal Control of Deep Space Science Missions,” 46th International Conference on Environmental Systems, Vienna, Austria, July 10–14, Paper No. ICES-2016-129.
Bar-Cohen, A. , Sheehan, J. R. , and Rahim, E. , 2012, “ Two-Phase Thermal Transport in Microgap Channels—Theory, Experimental Results, and Predictive Relations,” Microgravity Sci. Technol., 24(1), pp. 1–15. [CrossRef]
Bar-Cohen, A. , and Rahim, E. , 2009, “ Modeling and Prediction of Two-Phase Microgap Channel Heat Transfer Characteristics,” Heat Transfer Eng., 30(8), pp. 601–625. [CrossRef]
Alam, T. , Lee, P. S. , and Jin, L.-W. , 2014, Flow Boiling in Microgap Channels: Experiment, Visualization, and Analysis, Springer Science & Business Media, New York.
Taitel, Y. , 1990, “ Flow Pattern Transition in Two-Phase Flow,” Ninth International Heat Transfer Conference, Jerusalem, Israel, Aug. 19–24, pp. 237–254.
Kandlikar, S. G. , 2010, “ Scale Effects on Flow Boiling Heat Transfer in Microchannels: A Fundamental Perspective,” Int. J. Therm. Sci., 49(7), pp. 1073–1085. [CrossRef]
Robinson, F. , and Bar-Cohen, A. , 2017, “ Gravity Effects in Microgap Flow Boiling,” 16th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena Electronic Systems (ITherm), Orlando, FL, May 30 to June 2, pp. 480–491.
Ullmann, A. , and Brauner, N. , 2007, “ The Prediction of Flow Pattern Maps in Minichannels,” Multiphase Sci. Technol., 19(1), pp. 49–73. [CrossRef]
Baldassari, C. , and Marengo, M. , 2013, “ Flow Boiling in Microchannels in Microgravity,” Prog. Energy Combust. Sci., 39(1), pp. 1–36. [CrossRef]
Zhang, H. , Mudawar, I. , and Hasan, M. M. , 2009, “ Application of Flow Boiling for Thermal Management of Electronics in Microgravity and Reduced-Gravity Space Systems,” IEEE Trans. Compon. Packag. Tech., 32(2), pp. 466–477. [CrossRef]
Konishi, C. , Mudawar, I. , and Hasan, M. M. , 2013, “ Investigation of the Influence of Orientation on Critical Heat Flux for Flow Boiling With Two-Phase Inlet,” Int. J. Heat Mass Trans., 61, pp. 176–190. [CrossRef]
Kharangate, C. R. , Konishi, C. , and Mudawar, I. , 2016, “ Consolidated Methodology to Predicting Flow Boiling Critical Heat Flux for Inclined Channels in Earth Gravity and for Microgravity,” Int. J. Heat Mass Transfer, 92, pp. 467–482. [CrossRef]
Wang, C.-C. , Chang, W.-J. , Dai, C.-H. , Lin, Y.-T. , and Yang, K.-S. , 2012, “ Effect of Inclination on the Convective Boiling Performance of a Microchannel Heat Sink Using HFE-7100,” Exp. Therm. Fluid Sci., 36, pp. 143–148. [CrossRef]
Lee, H. , Park, I. , Mudawar, I. , and Hasan, M. M. , 2014, “ Micro-Channel Evaporator for Space Applications—1: Experimental Pressure Drop and Heat Transfer Results for Different Orientations in Earth Gravity,” Int. J. Heat Mass Transfer, 77, pp. 1213–1230. [CrossRef]
Lee, H. , Park, I. , Mudawar, I. , and Hasan, M. M. , 2014, “ Micro-Channel Evaporator for Space Applications—2: Assessment of Predictive Tools,” Int. J. Heat Mass Transfer, 77, pp. 1231–1249. [CrossRef]
Zhang, H. Y. , Pinjala, D. , and Wong, T. N. , 2005, “ Experimental Characterization of Flow Boiling Heat Dissipation in a Microchannel Heat Sink With Different Orientations,” Seventh Electronic Packaging Technology Conference, Singapore, Dec. 7–9, pp. 670–676.
Leão, H. , Chávez, C. A. , do Nascimento, F. J. , and Ribatski, G. , 2015, “ An Analysis of the Effect of the Footprint Orientation on the Thermal-Hydraulic Performance of a Microchannels Heat Sink During Flow Boiling of R245fa,” Appl. Therm. Eng., 90, pp. 907–926. [CrossRef]
Kandlikar, S. G. , and Balasubramanian, P. , 2005, “ An Experimental Study on the Effect of Gravitation Orientation on Flow Boiling of Water in 1054 × 197 μm Parallel Minichannels,” ASME J. Heat Trans., 127(8), pp. 820–829. [CrossRef]
Kandlikar, S. G. , 2012, “ History, Advances, and Challenges in Liquid Flow and Flow Boiling Heat Transfer in Microchannels: A Critical Review,” ASME J. Heat Trans., 134(3), p. 034001. [CrossRef]
Karayiannis, T. G. , and Mahmoud, M. M. , 2017, “ Flow Boiling in Microchannels: Fundamentals and Applications,” Appl. Therm. Eng., 115, pp. 1372–1397. [CrossRef]
Cheng, L. , and Xia, G. , 2017, “ Fundamental Issues, Mechanisms, and Models of Flow Boiling Heat Transfer in Microscale Channels,” Int. J. Heat Mass Trans., 108, pp. 97–127. [CrossRef]
Ohta, H. , Baba, A. , and Gabriel, K. , 2002, “ Review of Existing Research on Microgravity Boiling and Two-Phase Flow: Future Experiments on the International Space Station,” Ann. New York Acad. Sci., 974(1), pp. 410–427. [CrossRef]
Celata, G. P. , 2007, “ Flow Boiling Heat Transfer in Microgravity: Recent Results,” Microgravity Sci. Technol., 19(3–4), pp. 13–17. [CrossRef]
Konishi, C. , and Mudawar, I. , 2015, “ Review of Flow Boiling and Critical Heat Flux in Microgravity,” Int. J. Heat Mass Transfer, 80, pp. 469–493. [CrossRef]
Reynolds, W. C. , Saad, M. A. , and Satterlee, H. , 1964, “ Capillary Hydrostatics and Hydrodynamics at Low g,” Stanford University, Stanford, CA, Report No. LG-3.
Baba, S. , Ohtani, N. , Kawanami, O. , Inoue, K. , and Ohta, H. , 2012, “ Experiments on Dominant Force Regimes in Flow Boiling Using Mini-Tubes,” Front. Heat Mass Transfer, 3(4), pp. 1–8.
Rausch, M. , Kretschmer, L. , Stefan, W. , Leipertz, A. , and Fröba, A. P. , 2015, “ Density, Surface Tension, and Kinematic Viscosity of Hydrofluroethers HFE-7000, HFE-7100, HFE-7200, HFE-7300, and HFE-7500,” J. Chem. Eng. Data, 60(12), pp. 3759–3765. [CrossRef]
Qi, H. , Fang, D. , Meng, X. , and Wu, J. , 2014, “ Liquid Density of HFE-7000 and HFE-7100 From T = (283 to 363) K at Pressures Up to 100 MPa,” J. Chem. Thermodyn., 77, pp. 131–136. [CrossRef]
Zheng, Y. , Wei, Z. , and Song, X. , 2016, “ Measurements of Isobaric Heat Capacities for HFE-7000 and HFE-7100 at Different Temperatures and Pressures,” Fluid Phase Equilibria, 425, pp. 335–341. [CrossRef]
Klein, S. A. , 2018, “ Engineering Equation Solver: F-Chart Software Version 10.467,” F-Chart Software Company, Madison, WI.
Martin, J. J. , and Hou, Y.-C. , 1955, “ Development of an Equation of State for Gases,” AlChE J., 1(2), pp. 142–151. [CrossRef]
An, B. , Duan, Y. , Tan, L. , and Yang, Z. , 2015, “ Vapor Pressure of HFE 7100,” J. Chem. Eng. Data, 60(4), pp. 1206–1210. [CrossRef]
Sawada, K. , Kurimoto, T. , Okamoto, A. , Matsumoto, S. , Asano, H. , Kawanami, O. , Suzuki, K. , and Ohta, H. , 2014, “ Investigation of Dissolved Air Effects on Subcooled Flow Boiling Heat Transfer for Boiling Two-Phase Flow Experiment Onboard the ISS,” 44th International Conference on Environmental Systems, Tucson, AZ, July 13–17, Paper No. ICES-2014-228.
Chen, T. , and Garimella, S. V. , 2006, “ Effects of Dissolved Air on Subcooled Flow Boiling of a Dielectric Coolant in a Microchannel Heat Sink,” ASME J. Electron. Packag., 128(4), pp. 398–404. [CrossRef]
Müller-Steinhagen, H. , Epstein, N. , and Watkinson, A. , 1988, “ Effect of Dissolved Gases on Subcooled Flow Boiling Heat Transfer,” Chem. Eng. Process.: Process Intensification, 23(2), pp. 115–124. [CrossRef]
Rottländer, H. , Umrath, W. , and Voss, G. , 2016, “ Fundamentals of Leak Detection: Cat. No. 199 79_VA.02,” Leybold GmbH, Cologne, Germany, accessed Apr. 5, 2019, www.leyboldproducts.com/media/pdf/90/c7/87/Fundamentals_of_Leak_Detection_EN.pdf


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Fig. 1

Flow loop schematic

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Fig. 2

(a) Evaporator top view with thermal isolator cap removed and (b) evaporator axial cross section (to scale)

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Fig. 3

Evaporator orientations (not to scale)

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Fig. 4

Flow boiling CHF as a function of mass flux and evaporator orientation

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Fig. 5

Single- and two-phase HTCs as a function of heat flux, evaporator orientation, and mass flux

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Fig. 7

Flow boiling of HFE7100 in a 1.01 mm × 13.0 mm channel at mass flux 100 kg/m2 s and heat flux 53.6 kW/m2 (see Fig. 3 for gravity vector orientations)

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Fig. 6

HTC ratio among orientations as a function of heat flux and mass flux

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Fig. 8

Flow boiling of HFE7100 in a 1.01 mm × 13.0 mm channel at mass flux 300 kg/m2 s and heat flux 171.3 kW/m2 (see Fig. 3 for gravity vector orientations)

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Fig. 9

Dominant force maps with boundaries from Refs. [31] and [32] with data from this study

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Fig. 11

System COP as a function of mass flux and evaporator orientation

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Fig. 10

Dominant force maps with boundaries from Refs. [31] and [32] with data from Ref. [13]



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