There are many participants who have contributed to the work reported in this paper, including all the members of our project team, as well as some people from the Astronauts research and training center (ACC) and Neusoft.
This work is funded by the Strategic Priority Research Program on Space Science, Chinese Academy of Sciences: SJ-10 Recoverable Scientific Experiment Satellite (Grant No. XDA04020405 and XDA04020202-05), and by the joint fund of National Natural Science Foundation of China (U1738116).

1. Design and preparation of the experimental system
<ol>
	<li>Construct the annular liquid pool.
	<ol>
		<li>Build a copper annular liquid pool measuring Ri = 4 mm in inner diameter and Ro = 20 mm in outer diameter and d = 12 mm in height.</li>
		<li>Use a polysulfone plate measuring RP = 20 mm in diameter as the bottom of the liquid pool (see Table of Materials).</li>
		<li>Drill a small hole measuring &#981; = 2 mm in diameter close to the inner wall (6 mm away from the center of the circle) as the liquid injection hole.</li>
	</ol>
	</li>
	<li>Maintain the interface.
	<ol>
		<li>Add sharp corners (45&#176; angles) on the inner and outer side walls (Figure 2).</li>
		<li>Apply anti-creeping liquid21 (see Table of Materials) to the inner and outer walls to a height greater than 12 mm.</li>
	</ol>
	</li>
	<li>Prepare the storage system of working liquid.
	<ol>
		<li>Choose 2cSt silicone oil as the working liquid (see Table of Materials).</li>
		<li>Use a hydraulic cylinder as the container for storing the silicone oil (see Table of Materials).</li>
		<li>Inject the working fluid to the hydraulic cylinder using the bubble-free technique before launch. 
		NOTE: Bubbles suspended in the working fluid will result in the failure of the experiment.
		<ol>
			<li>Discharge the gas in the silicone oil by heating the liquid to 60 &#176;C and applying pressure &#60;150 Pa for about 6 h.</li>
			<li>Vacuum the liquid storage system until its pressure is &#60;200 Pa.</li>
			<li>Relieve the valve to allow the silicone oil to fill in the vacuumed cylinder without gas (Figure 3).</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Set up the injection system for the working liquid.
	<ol>
		<li>Select a step motor to drive the injection or suction of liquid (see Table of Materials).</li>
		<li>Apply a solenoid valve to control the on-off switch of the injection system (see Table of Materials).</li>
		<li>Connect the step motor to the liquid cylinder using a universal joint (Figure 4).</li>
		<li>Connect the liquid cylinder, solenoid valve, and injection hole successively with a pipe measuring 4 mm in outer diameter.</li>
	</ol>
	</li>
</ol>
2. Establishment of the temperature control system
<ol>
	<li>Embed the inner cylinder with a heating film (resistance Rt = 14.4 &#177; 0.5 &#937;) and measure the temperature Ti with a K-type thermocouple (see Table of Materials).</li>
	<li>Symmetrically attach six refrigeration chips (every two chips are connected in parallel as a group, and three groups are connected in a series) to the outer wall and obtain the outer wall temperature To using an additional K-type thermocouple. 
	NOTE: The temperature difference is &#916;T = Ti - To.</li>
</ol>
3. Establishment of the measurement system
NOTE: All devices can be controlled by software.
<ol>
	<li>Place six thermocouples (T1 - T6) inside the liquid pool to measure temperatures at different points. The detailed layout is shown in Figure 5.</li>
	<li>Place the infrared camera directly above the liquid surface, and rotate the lens to adjust the focus and collect the temperature field information on the liquid-free surface (see Table of Materials).</li>
	<li>Adjust the displacement sensor to measure the displacement of a certain point (r = 12 mm) on the liquid surface (see Table of Materials). 
	NOTE: The laser displacement sensor is used for this payload in order to realize a 100 &#181;s high-speed sampling, which is an ultra-high precision measurement method with a resolution of 1 &#181;m, and a linearity of &#177; 0.1% F.S.</li>
	<li>Use the CCD camerato focus on the liquid surface and record the change of the free surface (see Table of Materials, Figure 6). 
	NOTE: The number of effective pixels is 752 x 582, and the minimum illumination is 1.6 Lux/F2.0.</li>
</ol>
4. Experimental process
<ol>
	<li>Start the experiment control software and turn on the power button.</li>
	<li>Perform the liquid injection.
	<ol>
		<li>Apply 12 V on the solenoid valve to open it.</li>
		<li>Turn on the motor button to push the motorat a step of 2.059 mm and inject 10,305 mL of silicone oil into the liquid pool.</li>
		<li>Turn off the solenoid valve power to close the solenoid valve.</li>
	</ol>
	</li>
	<li>Perform linear heating.
	<ol>
		<li>Set the experimental conditions as follows: heating target temperature Ti = 50 &#176;C; cooling target temperature To = 15 &#176;C; and heating rate = 0.5 &#176;C/min.</li>
	</ol>
	</li>
	<li>Collect data.
	<ol>
		<li>Set the corresponding sampling frequencies of the infrared imager, thermocouples, displacement sensor, and CCD to 7.5 Hz, 20 Hz, 20 Hz, and 25 Hz respectively.</li>
		<li>Click the button for the data collecting system and monitor the temperature, displacement, and other information using the computer software (Figure 7).</li>
	</ol>
	</li>
	<li>Turn off the power button. 
	NOTE: Wait 1 h so that the temperatures of the hot and cold ends are equal to the ambient temperature for the following experiment.</li>
</ol>

<ol>
	<li>Scriven, L. E., Sternling, C. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Marangoni+effect.">The Marangoni effect.</a> Nature. 187, 186-188 (1960).</li><li>Effects of heating mode on steady antisymmetric thermocapillary flows in microgravity. Heat Transfer in Microgravity Systems, Trans. American Society of Mechanical Engineers Available from: <a target="_blank" href="https://heattransfer.asmedigitalcollection.asme.org/">https://heattransfer.asmedigitalcollection.asme.org/</a> (1994)</li><li>Benz, S., Schwabe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+three-dimensional+stationary+instability+in+dynamic+thermocapillary+shallow+cavities.">The three-dimensional stationary instability in dynamic thermocapillary shallow cavities.</a> Experiments in Fluids. 31, 409-416 (2001).</li><li>Schwabe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Buoyant-thermocapillary+and+pure+thermocapillary+convective+instabilities+in+Czochralski+systems.">Buoyant-thermocapillary and pure thermocapillary convective instabilities in Czochralski systems.</a> Journal of Crystal Growth. 237-239, 1849-1853 (2002).</li><li>Kamotani, Y., Ostrach, S., Pline, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+velocity+data+taken+in+surface+tension+drivenconvection+experiment+in+microgravity.">Analysis of velocity data taken in surface tension drivenconvection experiment in microgravity.</a> Physics of Fluids. 6, 3601-3609 (1994).</li><li>Kamotani, Y., Ostrach, S., Pline, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+thermocapillary+convection+experiment+in+microgravity.">A thermocapillary convection experiment in microgravity.</a> Journal of Heat Transfer. 117, 611-618 (1995).</li><li>Kamotani, Y., Ostrach, S., Pline, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Some+temperature+field+results+from+the+thermocapillary+flow+experiment+aboard+USML-2+spacelab.">Some temperature field results from the thermocapillary flow experiment aboard USML-2 spacelab.</a> Advances in Space Research. 22, 1189-1195 (1998).</li><li>Kamotani, Y., Ostrach, S., Masud, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microgravity+experiments+and+analysis+of+oscillatory+thermocapillary+flows+in+cylindrical+containers.">Microgravity experiments and analysis of oscillatory thermocapillary flows in cylindrical containers.</a> Journal of Fluid Mechanics. 410, 211-233 (2000).</li><li>Schwabe, D., Benz, S., Cramer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiment+on+the+Multi-roll-structure+of+thermocapillary+flow+in+side-heated+thin+liquid+layers.">Experiment on the Multi-roll-structure of thermocapillary flow in side-heated thin liquid layers.</a> Advances in Space Research. 24 (10), 1367-1373 (1999).</li><li>Schwabe, D., Benz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermocapillary+flow+instabilities+in+an+annulus+under+microgravity+results+of+the+experiment+MAGIA.">Thermocapillary flow instabilities in an annulus under microgravity results of the experiment MAGIA.</a> Advances in Space Research. 29, 629-638 (2002).</li><li>Kawamura, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Report+on+Microgravity+Experiments+of+Marangoni+Convection+Aboard+International+Space+Station.">Report on Microgravity Experiments of Marangoni Convection Aboard International Space Station.</a> Journal of Heat Transfer. 134 (3), 031005 (2012).</li><li>Sato, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrothermal+Wave+Instability+in+a+High-Aspect-Ratio+Liquid+Bridge+of+Pr+&gt;+200.">Hydrothermal Wave Instability in a High-Aspect-Ratio Liquid Bridge of Pr &gt; 200.</a> Microgravity Science and Technology. 25 (1), 43-58 (2013).</li><li>Yano, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Instability+and+associated+roll+structure+of+Marangoni+convection+in+high+Prandtl+number+liquid+bridge+with+large+aspect+ratio.">Instability and associated roll structure of Marangoni convection in high Prandtl number liquid bridge with large aspect ratio.</a> Physics of Fluids. 27 (2), 024108 (2015).</li><li>Yao, Y. L., Liu, Q. S., Zhang, P., Hu, L., Liu, F., Hu, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Space+Experiments+on+Thermocapillary+Convection+and+Marangoni+Convection+in+Two+Immiscible+Liquid+Layers.">Space Experiments on Thermocapillary Convection and Marangoni Convection in Two Immiscible Liquid Layers.</a> Journal of the Japan Society of Microgravity Application. 15, 394-398 (1998).</li><li>Zhang, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Space+experimental+device+on+Marangoni+drop+migrations+of+large+Reynolds+numbers.">Space experimental device on Marangoni drop migrations of large Reynolds numbers.</a> Science in China. 44 (6), 605-614 (2001).</li><li>Xie, J. C., Lin, H., Zhang, P., Liu, F., Hu, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+investigation+on+thermocapillary+drop+migration+at+large+Marangoni+number+in+reduced+gravity.">Experimental investigation on thermocapillary drop migration at large Marangoni number in reduced gravity.</a> Journal of Colloid and Interface Science. 285, 737-743 (2005).</li><li>Kang, Q., Cui, H. L., Hu, L., Duan, L., Hu, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Investigation+on+bubble+coalescence+under+non-uniform+temperature+distribution+in+reduced+gravity.">Experimental Investigation on bubble coalescence under non-uniform temperature distribution in reduced gravity.</a> Journal of Colloid and Interface Science. 310, 546-549 (2007).</li><li>Duan, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+real-time+March-Zehnder+interferometer+used+in+space+experiment.">The real-time March-Zehnder interferometer used in space experiment.</a> Microgravity Science and Technology. 20, 91-98 (2008).</li><li>Zhu, P., Zhou, B., Duan, L., Kang, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+of+surface+oscillation+in+thermocapillary+convection.">Characteristics of surface oscillation in thermocapillary convection.</a> Experimental Thermal and Fluid Science. 35, 1444-1450 (2011).</li><li>Zhu, P., Duan, L., Kang, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transition+to+chaos+in+thermocapillary+convection.">Transition to chaos in thermocapillary convection.</a> International Journal of Heat and Mass Transfer. 57, 457-464 (2013).</li><li>Kang, Q., Duan, L., Zhang, L., Yin, Y. L., Yang, J. S., Hu, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermocapillary+convection+experiment+facility+of+an+open+cylindrical+annuli+for+SJ-10+satellite.">Thermocapillary convection experiment facility of an open cylindrical annuli for SJ-10 satellite.</a> Microgravity Science and Technology. 28, 123-132 (2016).</li><li>Wang, J., Wu, D., Duan, L., Kang, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ground+Experiment+on+the+Instability+of+Buoyant-thermocapillary+Convection+in+Large+Scale+Liquid+Bridge+with+Large+Prandtl+Number.">Ground Experiment on the Instability of Buoyant-thermocapillary Convection in Large Scale Liquid Bridge with Large Prandtl Number.</a> International Journal of Heat and Mass Transfer. 108, 2107-2119 (2017).</li><li>Kang, Q., Jiang, H., Duan, L., Zhang, C., Hu, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Critical+Condition+and+Oscillation+-+Transition+Characteristics+of+Thermocapillary+Convection+in+the+Space+Experiment+on+SJ-10+Satellite.">The Critical Condition and Oscillation - Transition Characteristics of Thermocapillary Convection in the Space Experiment on SJ-10 Satellite.</a> International Journal of Heat and Mass Transfer. 135, 479-490 (2019).</li><li>Kang, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+volume+ratio+effect+on+flow+patterns+and+transition+processes+of+thermocapillary+convection.">The volume ratio effect on flow patterns and transition processes of thermocapillary convection.</a> Journal of Fluid Mechanics. 868 (108), 560-583 (2019).</li></ol>

We have nothing to disclose.

Due to the limitation of space resources, the volume of the equipment as a whole is only 400 mm &#215; 352 mm &#215; 322 mm, with a weight of only 22.9 &#177; 0.2 kg. This is very inconvenient when selecting and laying out experimental devices, and the establishment of the flow system becomes the critical step. Therefore, the increasing temperature difference is set at two ends of the liquid pool so that the fluid can generate a series of flow phenomena. In order to observe the entire process of the convection from stead...

Under microgravity conditions in space, many interesting physical phenomena are presented due to the absence of gravity. In a liquid with a free surface, there exists a new flow system (i.e. thermocapillary flow) that is caused by the temperature gradient or concentration gradient. Different from traditional convection on the ground, thermocapillary convection is a ubiquitous phenomenon in space environments. As it is a very important research subject in microgravity fluid physics, a number of experiments have been carried out in space as well as on the ground. Recently, space experimental studies were performed on thermocapillary convection on the SJ-10 recoverable scientific experiment satellite. The space experiment payload consisted of eight systems, namely a fluid experiment system, liquid storage and injection system, temperature control system, thermocouple measurement system, infrared thermal camera, displacement sensors, CCD image acquisition system, and electrical control system, as shown in Figure 1 (left). The space experiment payload for research on surface waves of thermocapillary convection is shown in Figure 1 (right). This study focused on the instability of flow, oscillation phenomena, and transitions, which are important characteristics in the transition process from laminar flow to chaos. Studies on these fundamental subjects have great significance for research regarding strong nonlinear flow.
Unlike buoyancy convection driven by volume force, thermocapillary convection is a phenomenon caused by surface tension within the interface between two immiscible fluids. The magnitude of surface tension changes with some scalar parameters, including temperature, solute concentration, and electric field strength. When these scalar fields distribute unevenly in the interface, there will be a surface tension gradient present on the free surface. The fluid on the free surface is driven by the surface tension gradient to move from the location with lesser surface tension to that with greater surface tension. This flow was first interpreted by an Italian physicist, Carlo Marangoni. Hence, it was named the &#34;Marangoni effect&#34;1. Marangoni flow on the free surface extends to the inner liquid by viscosity and as a result generates what is known as Marangoni convection.
Strictly speaking, for the fluid system with a free surface, thermocapillary convection and buoyancy convection always appear simultaneously under normal gravity. In general, for a macroscopic convective system, thermocapillary convection is a minor effect and is usually ignored in comparison with buoyancy convection. However, under the condition of a small-scale convective system or in the microgravity environment, buoyancy convection will be greatly weakened, or even disappear, and thermocapillary convection will become dominant in the flow system. For a long period of time, research has been focused on macro-scale buoyancy convection due to the limitations in human activities and research methods2,3,4. However, in recent decades, with the rapid development of modern science and technology such as aerospace, film, MEMS, and nonlinear science, the need for further research on thermocapillary convection has become increasingly urgent.
Studies regarding microgravity hydrodynamics have important academic significance and application prospects. Many dynamicists, physical chemists, biologists, and materials scientists have gathered to work in this field. Kamotani and Ostrach completed experiments on thermocapillary convection in an annular liquid pool under microgravity conditions2,5,6,7,8 and observed steady flow, oscillatory flow, and critical conditions. Schwabe et al. studied buoyant-thermocapillary convection in a similar annular liquid pool3,9 and found that the oscillatory flow first appeared as thermocapillary waves, and then turned to a more complex flow with the increase in temperature difference. In 2002, Schwabe and Benz et al. reported a group of experiments on thermocapillary convection in an annular liquid pool carried out on the Russian FOTON-12 satellite4,10. Their space experimental results were consistent with ground experimental results. Some Japanese scientists carried out three series of experiments on liquid bridge thermocapillary convection, named the Marangoni Experiment in Space (MEIS), on the International Space Station11,12,13. Some experimental equipment, including the camera, thermal imager, thermocouple sensors, and 3D-PTV and photochromic technology, were applied in these three tasks. The critical conditions of thermocapillary convection at different aspect ratios were determined, and three-dimensional (3D) flow structures were observed.
Over the past 30 years, microgravity science has undergone prolific development in China14,15,16, and a number of microgravity experiments have been conducted in space17,18. In the field of fluid physics, the first microgravity experiment was the study of two-layer fluid on the SJ-5 recoverable satellite in 1999, and the flow structure was obtained by the particle tracing method14. In 2004, the study on thermocapillary migration of a droplet was carried out on the SZ-4, and the relationship between migration velocity and critical Mach (Ma) number was obtained15,16. In 2005, the experimental study on multi-bubble thermocapillary migration was carried out on the JB-417, and the migration rules were obtained as the Ma number was increased to 8,000. Meanwhile, problems such as bubble merging were also studied. In 2006, the study on diffusion mass transfer was carried out on the SJ-8 recoverable satellite, the Mach-Zehnder interferometer was first applied in the space experiment, the process of diffusion mass transfer was observed, and the diffusion coefficient was evaluated18.
In recent years, a series of ground experimental studies focused on oscillation and bifurcation processes in thermocapillary convection have been carried out, and the coupled effect of buoyancy and thermocapillary force has been analyzed. Experimental results show that the buoyancy effect cannot be ignored in ground experiments, as it plays a dominant role in many cases19,20,21,22. In 2016, two microgravity experiments were carried out to research thermocapillary convection in the liquid bridge on the TG-2, and thermocapillary convection in the annular liquid pool on the SJ-10 recoverable satellite23,24. The present paper introduces the experimental payload of thermocapillary convection on the SJ10, and the space experiment results. These methods will be helpful in exploring the mechanism of thermocapillary oscillation.
In order to observe the convective pattern transition, temperature oscillation, and liquid-free surface deformation, six thermocouples, an infrared thermal camera, and a displacement sensor to quantify the frequency, amplitude, and other physical quantities of the oscillation were used. Through investigations on oscillation and transition in thermocapillary convection in space, the mechanism of thermocapillary convection in the microgravity environment, which provides scientific guidance for the growth of materials in space, can be discovered and understood. Furthermore, technological breakthroughs in such space experiments, such as the techniques of liquid surface maintenance and liquid injection without bubbles, will further enhance the simplicity and technical level of microgravity experiments in fluid physics.
This paper introduces the payload development and space experiment of the thermocapillary surface wave project carried out on the SJ-10 scientific experimental satellite. As a space experiment payload, this thermocapillary convection system has a strong anti-vibration ability to prevent violent shock, especially during the satellite launching process. In order to meet the requirements of remote operation, the space experiment process is controlled automatically, and the space experimental data can be transmitted to the Ground Signal Receiving Station of the Spacecraft and then to the scientists&#39; experimental platform.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>anti-creeping liquid</td>
			<td>3M</td>
			<td>EGC-1700</td>
			<td></td>
		</tr>
		<tr>
			<td>CCD</td>
			<td>WATTEC</td>
			<td>WAT-230VIVID</td>
			<td></td>
		</tr>
		<tr>
			<td>Displacement sensor</td>
			<td>Panasonic</td>
			<td>HL-C1</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating film</td>
			<td>HongYu</td>
			<td>125 Q/W335.1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydraulic cylinder</td>
			<td>FESTO</td>
			<td>ADVU-40-25-P-A</td>
			<td></td>
		</tr>
		<tr>
			<td>Infrared camera</td>
			<td>FLIR</td>
			<td>Tau2</td>
			<td></td>
		</tr>
		<tr>
			<td>LED</td>
			<td>693 Institute</td>
			<td>10257MW7C</td>
			<td></td>
		</tr>
		<tr>
			<td>Montor</td>
			<td>PI</td>
			<td>M-227</td>
			<td></td>
		</tr>
		<tr>
			<td>Montor controller</td>
			<td>PI</td>
			<td>C-863</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipe, 4mm</td>
			<td>FESTO</td>
			<td>PUN-4X0,75-GE</td>
			<td></td>
		</tr>
		<tr>
			<td>polysulfone plate</td>
			<td>507 Institute</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Refrigeration chip</td>
			<td>Zhongke</td>
			<td>9502/065/021M</td>
			<td></td>
		</tr>
		<tr>
			<td>Silicon oil, 2cSt</td>
			<td>Shin-Etsu</td>
			<td>KF-96</td>
			<td></td>
		</tr>
		<tr>
			<td>Solenoid</td>
			<td>FESTO</td>
			<td>MFH-2-M5</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature controller</td>
			<td>Eurotherm</td>
			<td>3304</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermocouple, K-type</td>
			<td>North University of China</td>
			<td>ZBDX-HTTK</td>
			<td></td>
		</tr>
	</tbody>
</table>

thermocapillary convection space experiment on the sj-10 recoverable satellite

Thermocapillary convection is an important research subject in microgravity fluid physics. The experimental study on surface waves of thermocapillary convection in an annular liquid pool is one of the 19 scientific experimental projects on the SJ-10 recoverable satellite. Presented is a design for a payload for space experimental study on thermocapillary convection that includes the experimental model, measurement system, and control system. The specifics for the construction of an experimental model of an annular liquid pool with variable volume ratios is provided. The fluid temperatures are recorded by six thermocouples with a high sensitivity of 0.05 &#176;C at different points. The temperature distributions on the liquid free surface are captured by means of an infrared thermal camera. The free surface deformation is detected by a displacement sensor with a high accuracy of 1 &#181;m. The experimental process is fully automated. The research is focused on thermocapillary oscillation phenomena on the liquid-free surface and convective pattern transitions through analyses of experimental data and images. This research will be helpful to understand the mechanism of thermocapillary convection and will offer further insights into the nonlinear characteristics, flow instability, and bifurcation transitions of thermocapillary convection.

The accurate volume ratio was defined, and the liquid surface topography was reconstructed based on the images captured by the CCD. The critical instability condition was determined, and the oscillation characteristics were studied through analyses on single point temperature signals and displacement oscillating signals. The structure of the flow field was obtained, and the transition of the flow pattern was determined through the change of the infrared image with time. The flow character...

Watch this Scientific Journal Video about Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite at JoVE.com

Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite

A protocol for the space payload design, the space experiment on thermocapillary convection, and analyses of experimental data and images are presented in this paper.

Thermocapillary convection is an important research subject in microgravity fluid physics. The experimental study on surface waves of thermocapillary ...

thermocapillary-convection-space-experiment-on-sj-10-recoverable

Research

Education

JoVE Journal

JoVE Core

Physics

Engineering

Unit 1

Gravitation

SCIENTISTS IN ACTION

6.4K Views.  Chinese Academy of Sciences. A protocol for the space payload design, the space experiment on thermocapillary convection, and analyses of experimental data and images are presented in this paper.

Video: Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite

Fabrication of Uniform Nanoscale Cavities via Silicon Direct Wafer Bonding

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned and bonded silicon wafers. Unlike confinements in porous materials often used for these types of experiments3, bonded wafers provide predesigned uniform spaces for confinement. The geometry of each cell is well known, which removes a large source of ambiguity in the interpretation of data.
Exceptionally flat, 5 cm diameter, 375 &#181;m thick Si wafers with about 1 &#181;m variation over the entire wafer can be obtained commercially (from Semiconductor Processing Company, for example). Thermal oxide is grown on the wafers to define the confinement dimension in the z-direction. A pattern is then etched in the oxide using lithographic techniques so as to create a desired enclosure upon bonding. A hole is drilled in one of the wafers (the top) to allow for the introduction of the liquid to be measured. The wafers are cleaned2 in RCA solutions and then put in a microclean chamber where they are rinsed with deionized water4. The wafers are bonded at RT and then annealed at ~1,100 &#176;C. This forms a strong and permanent bond. This process can be used to make uniform enclosures for measuring thermal and hydrodynamic properties of confined liquids from the nanometer to the micrometer scale.

A method for permanently bonding two silicon wafers so as to realize a uniform enclosure is described. This includes wafer preparation, cleaning, RT bonding, and annealing processes. The resulting bonded wafers (cells) have uniformity of enclosure ~1%1,2. The resulting geometry allows for measurements of confined liquids and gasses.

Measurements of the heat capacity and superfluid fraction of confined 4He have been performed near the lambda transition using lithographically patterned ...

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement is used. Here we operate a Nd:YAG laser at a frequency of 10 Hz at the fundamental wavelength of 1,064 nm. The 14 nsec pulses with anenergy of 190 mJ/pulse are focused to a 50 &#181;m spot size to generate a plasma from optical breakdown or laser ablation in air. The microplasma is imaged onto the entrance slit of a 0.6 m spectrometer, and spectra are recorded using an 1,800 grooves/mm grating an intensified linear diode array and optical multichannel analyzer (OMA) or an ICCD. Of interest are Stark-broadened atomic lines of the hydrogen Balmer series to infer electron density. We also elaborate on temperature measurements from diatomic emission spectra of aluminum monoxide (AlO), carbon (C2), cyanogen (CN), and titanium monoxide (TiO).
The experimental procedures include wavelength and sensitivity calibrations. Analysis of the recorded molecular spectra is accomplished by the fitting of data with tabulated line strengths. Furthermore, Monte-Carlo type simulations are performed to estimate the error margins. Time-resolved measurements are essential for the transient plasma commonly encountered in LIBS.

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

Time-resolved atomic and diatomic molecular species are measured using LIBS. The spectra are collected at various time delays following the generation of optical breakdown plasma with Nd:YAG laser radiation&#160;and are analyzed to infer electron density and temperature.

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement ...

Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many cases validated experimentally, for light weight or impact energy absorbing structures, as high surface area heat exchangers or electrodes, as implants to the body, and many more. Although great progress has been made in understanding their structure-properties relationships, the large number of different processing techniques, each producing material with different characteristics and structure, means that understanding of the individual effects of all aspects of structure is not complete. The replication process, where molten metal is infiltrated between grains of a removable preform material, allows a markedly high degree of control and has been used to good effect to elucidate some of these relationships. Nevertheless, the process has many steps that are dependent on individual &#8220;know-how&#8221;, and this paper aims to provide a detailed description of all stages of one embodiment of this processing method, using materials and equipment that would be relatively easy to set up in a research environment. The goal of this protocol and its variants is to produce metal foams in an effective and simple way, giving the possibility to tailor the outcome of the samples by modifying certain steps within the process. By following this, open cell aluminum foams with pore sizes of 1&#8211;2.36 mm diameter and 61% to 77% porosity can be obtained.

Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many ...

A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space

A simple Positron Emission Tomography (PET) prototype has been constructed to fully characterize its basic working principles. The PET prototype was created by coupling plastic scintillator crystals to photomultipliers or PMT&#39;s which are placed at opposing positions to detect two gamma rays emitted from a radioactive source, of which is placed in the geometric center of the PET set-up. The prototype consists of four detectors placed geometrically in a 20 cm diameter circle, and a radioactive source in the center. By moving the radioactive source centimeters from the center the system one is able to detect the displacement by measuring the time of flight difference between any two PMT&#39;s and, with this information, the system can calculate the virtual position in a graphical interface. In this way, the prototype reproduces the main principles of a PET system. It is capable to determine the real position of the source with intervals of 4 cm in 2 lines of detection taking less than 2 min.

We present a simple but well-constructed Positron Emission Tomography (PET) system and elucidate its basic working principles. The goal of this protocol is to guide the user in constructing and testing a simple PET system.

A simple Positron Emission Tomography (PET) prototype has been constructed to fully characterize its basic working principles. The PET prototype was ...

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.

We present a protocol for using a piezoelectrically-assisted tribometer and optical profilometer to investigate the dependence of ultrasonic wear and friction reduction on linear velocity, contact pressure, and surface properties.

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs within the interlayer space of semiconducting layered titania nanosheet (TNS) films was investigated here. Two types of intermediate films (i.e., TNS films containing methyl viologen (TNS/MV2+) and 2-ammoniumethanethiol (TNS/2-AET+)) were prepared. The two intermediate films were soaked in an aqueous tetrachloroauric(III) acid (HAuCl4) solution, whereby considerable amounts of Au(III) species were accommodated within the interlayer spaces of the TNS films. The two types of obtained films were then soaked in an aqueous sodium tetrahydroborate (NaBH4) solution, whereupon the color of the films immediately changed from colorless to purple, suggesting the formation of AuNPs within the TNS interlayer. When only TNS/MV2+ was used as the intermediate film, the color of the film gradually changed from metallic purple to dusty purple within 30 min, suggesting that aggregation of AuNPs had occurred. In contrast, this color change was suppressed by using the TNS/2-AET+ intermediate film, and the AuNPs were stabilized for over 4 months, as evidenced by the characteristic extinction (absorption and scattering) band from the AuNPs.

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Here, we present a protocol for the in situ synthesis of gold nanoparticles (AuNPs) within the interlayer space of layered titanate films without the aggregation of AuNPs. No spectral change was observed even after 4 months. The synthesized material has expected applications in catalysis, photo-catalysis, and the development of cost-effective plasmonic devices.

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs ...

Study of Siphon Breaker Experiment and Simulation for a Research Reactor

Under the design conditions of a research reactor, the siphon phenomenon induced by pipe rupture can cause continuous outward flow of water. To prevent this outflow, a control device is required. A siphon breaker is a type of safety device that can be utilized to control the loss of coolant water effectively.
To analyze the characteristics of siphon breaking, a real-scale experiment was conducted. From the results of the experiment, it was found that there are several design factors that affect the siphon breaking phenomenon. Therefore, there is a need to develop a theoretical model capable of predicting and analyzing the siphon breaking phenomenon under various design conditions. Using the experimental data, it was possible to formulate a theoretical model that accurately predicts the progress and the result of the siphon breaking phenomenon. The established theoretical model is based on fluid mechanics and incorporates the Chisholm model to analyze two-phase flow. From Bernoulli&#39;s equation, the velocity, quantity, undershooting height, water level, pressure, friction coefficient, and factors related to the two-phase flow could be obtained or calculated. Moreover, to utilize the model established in this study, a siphon breaker analysis and design program was developed. The simulation program operates on the theoretical model basis and returns the result as a graph. The user can confirm the possibility of the siphon breaking by checking the shape of the graph. Furthermore, saving the entire simulation result is possible and it can be used as a resource for analyzing the real siphon breaking system.
In conclusion, the user can confirm the status of the siphon breaking and design the siphon breaker system using the program developed in this study.

The siphon breaking phenomenon was investigated experimentally and a theoretical model was proposed. A simulation program based on the theoretical model was developed and the results of the simulation program were compared with experimental results. It was concluded that the results of the simulation program matched the experimental results well.

Under the design conditions of a research reactor, the siphon phenomenon induced by pipe rupture can cause continuous outward flow of water. To prevent ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...