Prospective of employing high porosity open-cell metal foams in passive cryogenic radiators for space applications

26th International Cryogenic Engineering Conference & International Cryogenic Materials Conference 2016

材料科学;物理学

Tisha, Dixit^1 ; Indranil, Ghosh^1

Cryogenic Engineering Centre, IIT Kharagpur, India^1

关键词: Characteristic properties;    Conduction radiations;    Constant temperature;    Heat transfer area;    Heat transfer rate;    Open-cell metal foams;    Radiative heat exchange;    Radiative heat transfer;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/171/1/012048/pdf
DOI  :  10.1088/1757-899X/171/1/012048

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Passive cryogenic radiators work on the principle of dissipating heat to the outer space purely by radiation. High porosity open-cell metal foams are a relatively new class of extended surfaces. These possess the advantages of high surface area density and low weight, characteristics which the space industry looks for. In case of radiative heat transfer, the porous nature of metal foams permits a deeper penetration of the incident radiation. Consequently, the heat transfer area participating in radiative heat exchange increases thereby enhancing the heat transfer rate. However, effective heat conduction in between the foam struts reduces as a result of the void spaces. These two conflicting phenomenon for radiation heat transfer in metal foams have been studied in this work. Similar to the foam conduction-convection heat transfer analysis, a conduction-radiation heat transfer model has been developed for metal foams in analogy with the conventional solid fin theory. Metal foams have been theoretically represented as simple cubic structures. A comparison of the radiative heat transfer through metal foams and solid fins attached to a surface having constant temperature has been presented. Effect of changes in foam characteristic properties such as porosity and pore density have also been studied.