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ENGINEERED CARBON FOAM FOR TEMPERATURE CONTROL APPLICATIONS

Almajali, Mohammad Rajab
http://rave.ohiolink.edu/etdc/view?acc_num=dayton1271365522

Abstract Details

2010, Doctor of Philosophy (Ph.D.), University of Dayton, Engineering.
The need for advanced thermal management materials is well recognized in the electronics and communication industries. An overall reduction in size of electronic components has lead to higher power dissipation and increased the necessity for innovative cooling designs. In response, material suppliers have developed and are continuing to develop, an increasing number of light weight thermal management materials. The new carbon foam is a low density and high thermal conductivity material which has the potential to radically improve heat transfer, thereby reducing size and weight of equipment while simultaneously increasing its efficiency and capabilities. However, carbon foam exhibits low strength and low heat capacity. The present work is intended to overcome these two main drawbacks using a combinatorial approach: (i) initially, copper coating was carried out to improve the thermo-mechanical properties of carbon foam. The thermal and mechanical properties of coated foam were measured using laser flash technique and compression test, respectively. An analytical model was developed to calculate the effective thermal conductivity. It was observed that the copper-coated carbon foam with 50% porosity can attain a thermal conductivity of 180 W/mK. The results from the analytical model were in a very good agreement with experimental results. The modulus increased from 4.5 MPa to 8.6 MPa and the plateau stress increased from 54 kPa to 171 kPa. The relationships between the measured properties and the copper weight ratio were determined. The above analyses demonstrated the significance of copper coating in tailoring carbon foam properties. (ii) Numerical and experimental studies were performed to analyze the phase change behavior of wax/foam composite encapsulated in metal casing. A two-energy equation model was solved using computational fluid dynamics software (CFD). Interfacial effects at the casing-composite junction and between the wax-foam surfaces and the capillary pressure within the foam matrix were investigated. These factors lowered the heat transfer rate considerably and the melting area was reduced by more than 23%. Two samples, coated and uncoated carbon foam, were infiltrated with PCM and subjected to a uniform heat load test in a vacuum. The coated foam showed excellent performance compared to the uncoated foam. (iii) Finally, the new engineered carbon foam was used as a heat sink and heat exchanger in a thermoelectric cooler for a cooling vest application. Using carbon foam as the core material for this application, the effective transfer of heat was significantly increased while reducing the size and weight of the heat exchanger.
Khalid Lafdi (Committee Chair)
Lawrance Flach (Committee Member)
Kelly Kissock (Committee Member)
C. William Lee (Committee Member)
Youssef Raffoul (Committee Member)
Engineering
CARBON FOAM; PCM; thermal; thermal conductivity; heat

Recommended Citations

Citations

  • Almajali, M. R. (2010). ENGINEERED CARBON FOAM FOR TEMPERATURE CONTROL APPLICATIONS [Doctoral dissertation, University of Dayton]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1271365522

    APA Style (7th edition)

  • Almajali, Mohammad. ENGINEERED CARBON FOAM FOR TEMPERATURE CONTROL APPLICATIONS. 2010. University of Dayton, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=dayton1271365522.

    MLA Style (8th edition)

  • Almajali, Mohammad. "ENGINEERED CARBON FOAM FOR TEMPERATURE CONTROL APPLICATIONS." Doctoral dissertation, University of Dayton, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1271365522

    Chicago Manual of Style (17th edition)

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This open access ETD is published by University of Dayton and OhioLINK.