Advanced electrically conductive thermal control material systems for space applications

1996 ◽  
Author(s):  
M. S. Deshpande ◽  
Y. Harada ◽  
Jason Vaughn
Keyword(s):  
Thermal Control ◽  
Control Material ◽  
Electrically Conductive ◽  
Space Applications ◽  
Material Systems

Effect of Sr Doping on Structure and Emittance of La1-xSrxMnO3 Smart Thermal Control Films

2014 ◽  
Vol 602-603 ◽  
pp. 902-905
Author(s):  
Yong Jun Shen ◽  
Chuan Bin Wang ◽  
Ling Li ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Thin Film ◽  
Smooth Surface ◽  
Pulsed Laser ◽  
Double Exchange ◽  
Thermal Control ◽  
Laser Deposition ◽  
Lanthanum Manganite ◽  
Infrared Emissivity ◽  
Control Material ◽  
Double Exchange Interaction

Sr-doped lanthanum manganite (La1-xSrxMnO3) is characteristic of thermochromic, which can act as a smart thermal control material used in the variable-emittance devices. In the present study, La1-xSrxMnO3 thin films were prepared on MgO(100) substrates by pulsed laser deposition, and the effect of Sr-doping (x = 0 ~ 0.4) on the structure and infrared emissivity was investigated. Single-phased La1-xSrxMnO3 films with (100)-orientation were obtained, which showed a dense texture with smooth surface. The ratio of Mn4+/Mn3+ in the films was increased with increasing Sr doping, leading to the enhancement in double-exchange interaction and electrical conductivity. As a result, the phase transition from metal to insulator was observed with the increasing of test temperature. For the La0.8Sr0.2MnO3 thin film, a large value of emittance (De = 0.28) was obtained, indicating good variable-emittance by appropriate Sr doping.

Multilayer Tuneable Emittance Coatings with Low Solar Absorptance for Improved Smart Thermal Control in Space Applications

2009 ◽  
Author(s):  
Emile Haddad ◽  
Roman V. Kruzelecky ◽  
Brian Wong ◽  
Wes Jamroz ◽  
Mohamed Soltani ◽  
...  
Keyword(s):  
Thermal Control ◽  
Space Applications ◽  
Solar Absorptance

scholarly journals Evaluation of Thermal Control Material using Dielectric Multi-layer Film for Spacecraft

Netsu Bussei ◽  
2021 ◽  
Vol 35 (1) ◽  
pp. 5-11
Author(s):  
Kota Tomioka ◽  
Sumitaka Tachikawa ◽  
Yuji Nagasaka
Keyword(s):  
Thermal Control ◽  
Control Material ◽  
Layer Film ◽  
Multi Layer Film

Experimental Study of Flexible Electrohydrodynamic Conduction Pumping for Electronics Cooling

2018 ◽  
Author(s):  
Nicolas Vayas Tobar ◽  
Pavolas N. Christidis ◽  
Nathaniel J. O'Connor ◽  
Michal Talmor ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Flexible Electronics ◽  
Electronics Cooling ◽  
Thermal Control ◽  
Stable Operation ◽  
Space Applications ◽  
Manufacturing Method ◽  
Micro Scale ◽  
Wide Range ◽  
And Performance ◽  
And Control

As modern day electronics develop, electronic devices become smaller, more powerful, and are expected to operate in more diverse configurations. However, the thermal control systems that help these devices maintain stable operation must advance as well to meet the demands. One such demand is the advent of flexible electronics for wearable technology, medical applications, and biology-inspired mechanisms. This paper presents the design and performance characteristics of a proof of concept for a flexible Electrohydrodynamic (EHD) pump, based on EHD conduction pumping technology in macro- and meso-scales. Unlike mechanical pumps, EHD conduction pumps have no moving parts, can be easily adjusted to the micro-scale, and have been shown to generate and control the flow of refrigerants for electronics cooling applications. However, these pumping devices have only been previously tested in rigid configurations unsuitable for use with flexible electronics. In this work, for the first time, the net flow generated by flexible EHD conduction pumps is measured on a flat-plane and in various bending configurations. In this behavioral characteristics study, the results show that the flexible EHD conduction pumps are capable of generating significant flow velocities in all size scales considered in this study, with and without bending. This study also proves the viability of screen printing as a manufacturing method for these pumps. EHD conduction pumping technology shows potential for use in a wide range of terrestrial and space applications, including thermal control of rigid as well as flexible electronics, flow generation and control in micro-scale heat exchangers and other thermal devices, as well as cooling of high power electrical systems, soft robotic actuators, and medical devices.

Performance of Elastomeric Silicones in Ablative and Space Environments

1966 ◽  
Vol 39 (4) ◽  
pp. 1247-1257 ◽  
Author(s):  
Clyde L. Whipple ◽  
John A. Thorne
Keyword(s):  
High Vacuum ◽  
Thermal Control ◽  
Heat Fluxes ◽  
Space Environment ◽  
Space Applications ◽  
Wide Range ◽  
Environmental Extremes ◽  
Temperature Ranges ◽  
Space Environments ◽  
Thermal Control Coatings

Abstract Elastomeric silicones are among the best materials available for many ablative and space applications. In ablative applications, these materials protect launching equipment, safeguard various parts of vehicles and spacecraft during flight, and shield re-entering spacecraft. Generally, elastomeric silicones are used where ablative conditions involve low to moderate heat fluxes and shear forces. Ablative characteristics of materials can vary widely depending on polymer type, fillers, and applications techniques, and no one elastomeric silicone will perform in a wide range of ablative missions. A good knowledge of the ablative characteristics of silicone materials is required to select the best candidates for a given application. In the space environment, silicones are often used for seals, thermal control coatings, potting materials, and other applications because they perform well over wide temperature ranges, and because they are inherently stable to high-vacuum and ultraviolet conditions. Data given in this paper illustrate that silicones show little weight loss or loss of properties on exposure to space environmental extremes. Furthermore, these losses can be made almost negligible by proper conditioning of the finished elastomer.

Fundamental Study of Vapor Chamber Thermal Control Devices for Space Applications

2018 ◽  
Vol 2018 (0) ◽  
pp. 0207
Author(s):  
Soumei Baba ◽  
Kenichiro Sawada ◽  
Kohsuke Tanaka ◽  
Atsushi Okamoto
Keyword(s):  
Thermal Control ◽  
Vapor Chamber ◽  
Fundamental Study ◽  
Space Applications ◽  
Control Devices

scholarly journals Langstroth hive construction with cement-vermiculite

2004 ◽  
Vol 61 (6) ◽  
pp. 573-578 ◽  
Author(s):  
Maria Cristina Affonso Lorenzon ◽  
Rodolfo Gonçalves Cidreira ◽  
Edmundo Henrique Ventura Rodrigues ◽  
Milton Sérgio Dornelles ◽  
Geraldo Pereira Jr
Keyword(s):  
Thermal Conductivity ◽  
Honey Bees ◽  
Production Cost ◽  
Low Cost ◽  
Thermal Control ◽  
Light Weight ◽  
Control Material ◽  
Insulating Material ◽  
Randomized Design ◽  
Completely Randomized Design

Exfoliated vermiculite is a light-weight and cheap product that, because of its thermal resistance, has become a valuable insulating material. With regard to its use in beekeeping, this research tested whether the box for honey bees constructed with cement-vermiculite mortar (CVM) presents physical characteristics similar to those of wood. The experiment was carried out at Seropédica, RJ, Brazil, for eight months. The cement-vermiculite mortar was compared with a control material (pinewood), in the construction of Langstroth boxes and boards, in a completely randomized design, with respect to thermal control, thermal conductivity and its capacity to absorb and lose water. The production cost for a CVM box was estimated. There were no internal temperature differences between CVM and wooden boxes. Thermal conductivity values for CVM and pinewood were similar. CVM absorbed more water and lost water faster than pinewood. Since CVM boxes can be easily constructed, at a low cost and with similar characteristics as traditional boxes, made of wood, the material can be recommended for use in non-migratory beekeeping.

Effects of a Void Beneath a Kapton Heater Patch in a Vacuum

2004 ◽  
Author(s):  
Ryan A. Schmidt
Keyword(s):  
Heat Flux ◽  
Hot Spot ◽  
Thermal Control ◽  
Heat Fluxes ◽  
Void Size ◽  
Conduction Path ◽  
Space Applications ◽  
Affected Area ◽  
Conduction Pathway ◽  
Substrate Temperatures

The vacuum of space can lead to some interesting heater problems. In many space applications, heater patches consisting of Inconel elements joined together with Teflon sandwiched together between two Kapton layers are bonded to a structure (substrate) to provide thermal control. A void between the heater patch and the substrate can lead to a hot spot due to the loss of conduction path from the heater to the substrate. When the heater is in a vacuum with a void beneath it, heat is transferred to the substrate by radiation and fin effects through the heater and then to the substrate. The localized hot spot can cause heater layers to separate and further reduce the conduction pathway from the affected area and eventually burnout the heater. A large enough void combined with high heater heat fluxes and substrate temperatures can induce heater failures. For this paper the sensitivity of peak temperature with respect to heat flux (power density), substrate temperature, void size, and void location is considered.

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