Constrained Vapor Bubble (CVB) - 08.18.16
Constrained Vapor Bubble (CVB) aims to achieve a better understanding of the physics of evaporation and condensation and how they affect cooling processes in microgravity using a remotely controlled microscope and a small cooling device. Science Results for Everyone
When electronics generate heat in spacecraft, astronauts can’t just open a window to cool things off. This investigation used a wickless heat pipe to better understand how evaporation and condensation affect cooling processes in microgravity. These devices are well-suited to use in space because they contain no moving parts that might need replacement. Researchers observed unanticipated bubble formations, originating at the heater surface and closely followed by an increase of about 10 percent in the overall heat transfer rate. Using these results, researchers developed simple models of bubble formation, which could help develop more efficient microelectronics cooling systems. Experiment Details
Peter C. Wayner, Jr., Ph.D., Rensselaer Polytechnic Institute, Troy, NY, United States
Joel L. Plawsky, Sc.D.,, Rensselaer Polytechnic Institute, Troy, NY, United States
ZIN Technologies Incorporated, Cleveland, OH, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
March 2010 - September 2011
CVB began operations during ISS Expedition 19/20.
- Certain types of cooling devices, known as wickless heat pipes, contain no moving parts and as a result are highly reliable as cooling equipment for space where access to replacement parts is difficult or impossible.
- The results from these experiments could lead to the development of more efficient cooling systems in microelectronics on earth and in space.
The thermophysical principles underlying change-of-phase heat transfer systems are not well understood in microgravity conditions and are less than optimized even in earth gravity. This experiment proposes basic experimental and theoretical studies of the nonisothermal Constrained Vapor Bubble (CVB) under microgravity conditions. The CVB represents a passive, wickless heat pipe ideally suited to obtain engineering and fundamental data on phase change heat transfer driven by interfacial phenomena. The proposed study represents a basic scientific study in interfacial phenomena, microgravity fluid physics and thermodynamics, a basic study in thermal transport and an engineering study of a passive heat exchanger. This optical study of vapor bubbles constrained in transparent glass cells at variable temperature increases the basic understanding of heat and mass transfer at phase-change interfaces. The information obtained from the study optimizes the design and operation of passive heat transfer devices for earth and microgravity environments and is critically important for the successful completion of long-term lunar and Mars missions.
In this experiment, the crewmember determines the pressure and temperature gradients driving flow through the heat-exchanger optically by measuring the shape of the vapor-liquid interface. Due to their sensitivity to gravity and to small temperature and pressure gradients, these transport systems need to be studied under microgravity conditions to obtain some essential, fundamental information.
The engineering objectives are to determine the stability, the fluid flow characteristics, the average heat transfer coefficient in the evaporation region, and the heat conductance of the CVB as a function of the heat flow rate and vapor volume. The experiment aims to determine the detailed characteristics of the transport processes in a curved liquid film.
NASA and ZIN Technologies developed the experimental setup for flight aboard the International Space Station as a part of the Fluids Integrated Rack (FIR). The Light Microscopy Module (LMM) developed as a part of the FIR consists of a completely automated optical microscope performs a variety of experiments. One of the first experiments intended for the LMM is the CVB experiment.
The assembly consists of a quartz cuvette that is closed at one end. The cuvette cavity is 3 mm 3 mm on the inside and is about 30 mm long. The thickness of the cuvette wall is 1.25 mm, making the outside dimension 5.5 mm 5.5 mm. Thermocouples are attached to the outside surface of the quartz cuvette by drilling holes into the surface of the quartz. A heater is attached to supply heat for evaporation of the working fluid at the closed end of the cuvette. The heater is insulated from all sides so that all the electrical heat input goes into the cuvette only. The open end is sealed with a cold finger that is kept at a constant known low temperature and drains the heat away. To measure pressure, a pressure transducer is attached to the assembly. The cold finger has small holes built into it to create a continuous liquid phase in order to transmit the pressure. The crewmember views the inside surface of the cuvette with the microscope. The CVB module is designed in such a way that the entire assembly containing the experiment cuvette, the thermocouple assembly and the pressure transducer makes a module which can be easily inserted into the Light Microscopy Module. The module is mounted on a moveable stage with x, y and z axis motion to bring regions of the cuvette in the field of view of the microscope objective. The x and y stage movement moves the cuvette while the z movement helps in focusing the image. Lastly, the entire LMM can be tilted around its axis so that the cuvette assembly can be oriented perpendicular or horizontal to gravity.
CVB has performed ground-based studies in a thermal vacuum chamber to determine the efficiency of the heater and cooler configuration. Large thermal response times that have been experimentally observed in space-based experiments cannot be obtained from these ground-based studies. Space-based experimentation is the only method available to ascertain internal low-gravity fluid mechanics within a heat pipe.
The project aims to achieve an improved understanding of microscale heat transfer, improved designs for wickless heat pipes, and an increased efficiency in heat transfer devices for cooling critical components. Targeted users are existing microelectronics industry and perhaps military applications. New designs should be able to be developed several months following the analysis and presentation of the results from the experiment.
Operational Requirements and Protocols
Several different CVB science modules are developed with different lengths (20 mm, 30 mm and 40 mm). A microscope inside LMM images the length of the science module at different heat settings. The images are sent to the earth for analysis.
Decadal Survey Recommendations
Applied Physical Science in Space AP1
Applied Physical Science in Space AP2
Kundan A, Plawsky JL, Wayner, Jr. PC. Thermophysical characteristics of a wickless heat pipe in microgravity – Constrained vapor bubble experiment. International Journal of Heat and Mass Transfer. 2014 November; 78: 1105-1113. DOI: 10.1016/j.ijheatmasstransfer.2014.07.044.
Kundan A, Plawsky JL, Wayner, Jr. PC. Effect of capillary and marangoni forces on transport phenomena in microgravity. Langmuir. 2015 April 15; epub. DOI: 10.1021/acs.langmuir.5b00428. PMID: 25874586.
Nguyen TT, Kundan A, Wayner, Jr. PC, Plawsky JL, Chao DF, Sicker RJ. The effect of an ideal fluid mixture on the evaporator performance of a heat pipe in microgravity. International Journal of Heat and Mass Transfer. 2016 April; 95: 765-772. DOI: 10.1016/j.ijheatmasstransfer.2015.12.032.
Kundan A, Nguyen TT, Plawsky JL, Wayner, Jr. PC, Chao DF, Sicker RJ. Arresting the phenomenon of heater flooding in a wickless heat pipe in microgravity. International Journal of Multiphase Flow. 2016 June; 82: 65-73. DOI: 10.1016/j.ijmultiphaseflow.2016.02.001.
Chatterjee A, Plawsky JL, Wayner, Jr. PC, Chao DF, Sicker RJ, Lorik T, Chestney L, Margie R, Eustace J, Zoldak JT. Constrained Vapor Bubble Heat Pipe Experiment Aboard the International Space Station . Journal of Thermophysics and Heat Transfer. 2013 March; 27(2): 309-319. DOI: 10.2514/1.T3792.
Kundan A, Plawsky JL, Wayner, Jr. PC, Chao DF, Sicker RJ, Motil BJ, Lorik T, Chestney L, Eustace J, Zoldak JT. Thermocapillary phenomena and performance limitations of a wickless heat pipe in microgravity. Physical Review Letters. 2015 April 7; 114(14): 146105. DOI: 10.1103/PhysRevLett.114.146105. PMID: 25910141.
Chatterjee A, Plawsky JL, Wayner, Jr. PC, Chao DF, Sicker RJ, Lorik T, Chestney L, Eustace J, Zoldak JT. The Constrained Vapor Bubble (CVB) Experiment in the Microgravity Environment of the International Space Station. 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Orlando, FL; 2011 January 4-7
Plawsky JL, Wayner, Jr. PC. Explosive Nucleation in Microgravity: The Constrained Vapor Bubble Experiment. International Journal of Heat and Mass Transfer. 2012 November; 55(23-24): 6473-6484. DOI: 10.1016/j.ijheatmasstransfer.2012.06.047.
Ground Based Results Publications
Chatterjee A, Plawsky JL, Wayner, Jr. PC, Chao DF, Sicker RJ, Lorik T, Chestney L, Eustace J, Zoldak JT. The Constrained Vapor Bubble Experiment for ISS - Earth's Gravity Results. Journal of Thermophysics and Heat Transfer. 2010; 24(4): 400-410. DOI: 10.2514/1.47522. [Also presented at the 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, Orlando, Florida, January 4 - 7, 2010 (AIAA 2010-1481).]
Gokhale SJ, Plawsky JL, Wayner, Jr. PC. Spreading, Evaporation and Contact Line Dynamics of Surfactant Laden Micro-Drops. Langmuir. 2005; 21(18): 8188-8197. DOI: 10.1021/la050603u.
Ojha M, Chatterjee A, Dalakos G, Wayner, Jr. PC, Plawsky JL. Role of solid surface structure on evaporative phase change from a completely wetting corner meniscus. Physics of Fluids. 2010; 22(5): 052101. DOI: 10.1063/1.3392771.
Chatterjee A, Plawsky JL, Wayner, Jr. PC. A Boundary Value Model for an Evaporating Meniscus. Proceedings of the 14th International Heat Transfer Conference, Washington, DC; 2010 August 8-13 827-834.
Plawsky JL, Panchangam SS, Gokhale SJ, Wayner, Jr. PC, DasGupta S. A Study of the Oscillating Corner Meniscus in a Vertical Constrained Vapor Bubble System. Superlattices and Microstructures. 2004; 35: 559-572.
Chatterjee A, Plawsky JL, Wayner, Jr. PC. Disjoining pressure and capillarity in the constrained vapor bubble heat transfer system. Advances in Colloid and Interface Science. 2011 October; 168(1-2): 40-49. DOI: 10.1016/j.cis.2011.02.011.
Ojha M, Chatterjee A, Mont F, Schubert EF, Wayner, Jr. PC, Plawsky JL. The role of solid surface structure on dropwise phase change processes. International Journal of Heat and Mass Transfer. 2010 February; 53(5-6): 910-922. DOI: 10.1016/j.ijheatmasstransfer.2009.11.033.
Gokhale SJ, Plawsky JL, Wayner, Jr. PC, DasGupta S. Inferred pressure gradient and fluid flow in a condensing sessile droplet based on the measured thickness profile. Physics of Fluids. 2004; 16(6): 1942-1955.
Zheng L, Plawsky JL, Wayner, Jr. PC, DasGupta S. Stability and Oscillations in an Evaporating Corner Mensicus. Journal of Heat Transfer. 2004; 126: 169.
Panchangam SS, Plawsky JL, Wayner, Jr. PC. Influence of Marangoni Stresses and Slip on Spreading Characteristics of an Evaporating Binary Mixture Meniscus. 9th AIAA/ASME Joint Thermophysics and Heat Transfer Conference; 2006 2006-3271.
Plawsky JL, Ojha M, Chatterjee A, Wayner, Jr. PC. Review of the Effects of Surface Topography, Surface Chemistry, and Fluid Physics on Evapoation at the Contact Line. Chemical Engineering Communications. 2008 December 15; 196(5): 658-696. DOI: 10.1080/00986440802569679.
Panchangam SS, Plawsky JL, Wayner, Jr. PC. Microscale Heat Transfer in an Evaporating Moving Extended Meniscus. Experimental Thermal and Fluid Science. 2006; 30: 245.
Chatterjee A, Wayner, Jr. PC, Plawsky JL, Chao DF, Sicker RJ, Lorik T, Chestney L, Eustace J, Margie R, Zoldak JT. The Constrained Vapor Bubble Fin Heat Pipe in Microgravity. Industrial & Engineering Chemistry Research. 2011 August 3; 50(15): 8917-8926. DOI: 10.1021/ie102072m.
Gokhale SJ, DasGupta S, Plawsky JL, Wayner, Jr. PC. Reflectivity Based Evaluation of the Coalescence of Two Condensing Drops and Shape Evolution of the Coalesced Drop. Physical Review E, Statistical, Nonlinear, and Soft Matter. 2004; 70(5): 051610.
Panchangam SS, Plawsky JL, Wayner, Jr. PC. Spreading Characteristics and Microscale Evaporative Heat Transfer in an Ultra-Thin Film Containing a Binary Mixture. Journal of Heat Transfer. 2006; 128: 1266.
Panchangam SS, Gokhale SJ, Plawsky JL, DasGupta S, Wayner, Jr. PC. Experimental Determination of the Effect of Disjoining Pressure on Shear in the Contact Line Region of a Moving Evaporating Thin Film. Journal of Heat Transfer. 2005; 127: 231-243.
Gokhale SJ, DasGupta S, Plawsky JL, Wayner, Jr. PC. Optical Investigation of the Interfacial Phenomena During Coalescence of two Condensing Drops and Shape Evolution of the Coalesced Drop. 2004 American Institute of Chemical Engineers Annual Meeting, Austin, TX; 2004
ISS Research Project-CVB
Image of the experimental setup. The CVB module opened. The thermocouples are embedded in the surface of the quartz. The cold finger is connected to the copper base plate to provide a large heat sink. Image courtesy of Glenn Research Center.
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Image taken by the surveillance camera in the Light Microscopy Module on board the ISS during initial oerations from March 22 - 24, 2010. Composite microscope images shows the bubble symmetry and the change of state from vapor to liquid in microgravity
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Composite microscope images show the bubble symmetry and the change of state from vapor to liquid in microgravity. Fringe pattern images demonstrate the near perfect symmetry of the bubble which allows greater liquid flow in microgravity. Image courtesy of Glenn Research Center.
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Image courtesy of Glenn Research Center.
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Image courtesy of Glenn Research Center.
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