Understanding Trade-Offs of Phase Change Materials for Transient Thermal Mitigation

2019 ◽  
Author(s):  
Lauren Boteler ◽  
Michael Fish ◽  
Morris Berman ◽  
Justin Wang
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Trade Offs ◽  
Transient Thermal ◽  
Thermal Mitigation

Evolutionary Insights into the State-of-the-Art Passive Thermal Control Systems for Thermodynamic Stability of Smallsats

2020 ◽  
Vol 35 ◽  
pp. 29-45
Author(s):  
Pratik Walimbe ◽  
Shubham Padekar
Keyword(s):  
Phase Change ◽  
Control Systems ◽  
Phase Change Materials ◽  
Thermal Environment ◽  
Temperature Drop ◽  
Direct Consequence ◽  
Thermal Control ◽  
Excessive Heat ◽  
Trade Offs ◽  
Surface Finishes

‘Smallsats,’ originated in the 1990s and popularized again since 2005, is a newly emerging miniaturized form of conventional satellites. Characterized by low mass (usually under 500 kg) and compact dimensions, Smallsats are one of the most sought-after forms of satellites, thanks to the ease offered by the lightweight. However, this privilege brings with itself the significant impediments such as excessive heat generation arising from the compact stature during peak hours of operation, external heat load as a result of radiation. These heat loads manifest themselves as the direct solar flux, earth’s albedo, and earth’s infrared radiation. Sudden temperature drop within the eclipse region results in the permanent-equipmental damage of the electronic circuitry involved, the direct consequence of which is the out-of-tolerance performance of the satellite. Thermal Control Systems (TCS) is the most plausible solution in this regard whose chief objective in any spacecraft or a satellite is to maintain all the subsystems along with the payload components within the stipulated temperature limits for each mission phase. This paper presents the passive thermal control systems (PTCS) in cube-sats. Starting with the discussion of the thermal environment, typical concepts like albedo, earth IR are shed light on. Subsequent discussions follow the study of thermal surface finishes and multi-layer insulations (MLI). Finally, the applications of phase-change materials (PCM) in thermal control systems of cube-sats are introduced. The constant trade-offs between the optimal thermal finish and the overall performance, arising due to incurrence of contamination during synthesis, SLI-MLI thickness and cost associated with increasing thickness and the phase-change materials (PCM’s) and their compatibility, have always been at the pin-point of the research. The widespread importance of thermal control systems is attributed to its ability to ensure the meetings of the gradient requirements, a parameter playing a crucial role in spacecraft dynamics.

An Investigation Into the Penetration of Phase Change Material in Carbon Foam for Transient Thermal Management

2009 ◽  
Author(s):  
Omar Sanusi ◽  
Randy D. Weinstein ◽  
Amy S. Fleischer
Keyword(s):  
Phase Change ◽  
Thermal Management ◽  
Phase Change Materials ◽  
High Capacity ◽  
Carbon Foam ◽  
Storage Device ◽  
Foam Structure ◽  
Transient Thermal ◽  
Change Material ◽  
Initial Research

Phase Change Materials (PCMs) are used for thermal management and are ideal for cyclic operations due to their high capacity to store heat. Most PCMs do not exhibit sufficient conductivity to be effective at larger sizes. Enhancing conductivity can be done in a number of ways including carbon foam. It is not widely known how well PCMs penetrate inside the carbon foam structure. Initial research suggests that the carbon foam-PCM matrix acts more as a conductor than a thermal storage device. Through the use microscopy, we will examine how the well the PCM penetrates into the carbon foam. We will also use experimental data comparing carbon foam enhanced modules to pure PCM modules. A volume displacement test will also be used to determine the quantity of PCM that enters into the carbon foam structure. This knowledge will allow better design of enhanced PCM modules and will determine if carbon foam is indeed a viable conduction enhancer for PCM thermal management.

Transient thermal response of multi-walled carbon nanotube phase change materials in building walls

Energy ◽  
2021 ◽  
Vol 224 ◽  
pp. 120120
Author(s):  
Hamid Sarrafha ◽  
Alibakhsh Kasaeian ◽  
Mohammad Hossein Jahangir ◽  
Robert A. Taylor
Keyword(s):  
Carbon Nanotube ◽  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Response ◽  
Multi Walled Carbon Nanotube ◽  
Transient Thermal ◽  
Building Walls ◽  
Transient Thermal Response

Thermal Analysis of Phase Change Materials With Embedded Graphite Nanofibers for Thermal Management of Electronics

2006 ◽  
Author(s):  
Thomas C. Kopec ◽  
Randy D. Weinstein ◽  
Amy S. Fleischer ◽  
Elizabeth D'Addio ◽  
Carol A. Bessel
Keyword(s):  
Phase Change ◽  
Thermal Management ◽  
Phase Change Materials ◽  
Thermal Response ◽  
Weight Percent ◽  
Fiber Loading ◽  
Graphite Nanofibers ◽  
Thermal Management Of Electronics ◽  
Cubic System ◽  
Transient Thermal

Phase change materials (PCMs) exhibit excellent thermal storage capacity due to their high latent heat of transformation and have been successfully utilized in small volumes for transient thermal management of electronics. However, their low thermal diffusivity makes it difficult to utilize large volumes of PCMs for transient thermal management of high power density systems. To improve the thermal performance of a paraffin PCM, high thermal conductivity graphite nanofibers are embedded into the paraffin PCM. The thermal effects of graphite fiber loading levels, measured in weight percent, are examined for a 131 cm3 volume cubic system with power loads of 3 and 7 W. It is found that the thermal response of the system improves with increased fiber loading levels.

Transient Thermal Management of a Handset Using Phase Change Material (PCM)

2002 ◽  
Vol 124 (4) ◽  
pp. 419-426 ◽  
Author(s):  
Marc Hodes ◽  
Randy D. Weinstein ◽  
Stephen J. Pence ◽  
Jason M. Piccini ◽  
Lou Manzione ◽  
...  
Keyword(s):  
Steady State ◽  
Phase Change ◽  
Thermal Management ◽  
Phase Change Materials ◽  
Maximum Temperature ◽  
Ir Camera ◽  
Steady State Heat ◽  
Steady State Heat Transfer ◽  
Time Required ◽  
Transient Thermal

The power density of portable electronic devices continues to increase because packaging advances reduce their size even as features are added and enhanced. Designing thermal management systems to accommodate steady-state conditions as opposed to fixed duty cycles can substantially increase cost, size, and weight. The feasibility of transient thermal management of handsets using phase change materials (PCMs) was experimentally investigated using an ABS handset mock-up. At selected intervals of time, the nonuniform case temperature of the handset was measured using an infrared (IR) camera, while thermocouples measured the temperatures of the PCM and simulated power amplifier (heater). Transient and steady-state heat transfer rates by natural convective and radiation from the handset to the environment were numerically computed from the temperature data in the thermal images. The effects of PCM material, power supplied to the handset, and handset orientation on the time required for the handset case to reach a given (maximum) temperature and “recovery” time were examined.

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