scholarly journals CFD study on thermal transport in open-cell metal foams with and without a washcoat: Effective thermal conductivity and gas-solid interfacial heat transfer

2017 ◽  
Vol 161 ◽  
pp. 92-108 ◽  
Author(s):  
Wenping Peng ◽  
Min Xu ◽  
Xunfeng Li ◽  
Xiulan Huai ◽  
Zhigang Liu ◽  
...  
2019 ◽  
Vol 9 (8) ◽  
pp. 861-871
Author(s):  
Milad Saljooghi ◽  
Younes Bakhshan ◽  
Saeid Niazi ◽  
Jamshid Khorshidi

The Conception of thermo-physical properties of porous materials is a challenging task for scientists to conquer. The open cell metal foam increases heat transfer while energy dissipation, dimension and density of them which are constraints for modern technologies significantly reduce. In the present study, the open cell metal foams with four kinds of structures have been investigated numerically and experimentally and the effective thermal conductivity (ETC) of them have been extracted with using different base fluids such as water, air and paraffin. Also, various metals have been considered copper, aluminum, nickel and silver. Finally, a validated correlation for calculation of ETC of open cell metal foams has been developed which is function of thermal conductivity of fluid and metal, porosity and geometrical properties of pore that is applicable for all open cell metal foam approximately. The results show, good agreements between the modeling results and experimental data.


2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Karthik K. Bodla ◽  
Jayathi Y. Murthy ◽  
Suresh V. Garimella

Porous sintered microstructures are critical to the functioning of passive heat transport devices such as heat pipes. The topology and microstructure of the porous wick play a crucial role in determining the thermal performance of such devices. Three sintered copper wick samples employed in commercial heat pipes are characterized in this work in terms of their thermal transport properties––porosity, effective thermal conductivity, permeability, and interfacial heat transfer coefficient. The commercially available samples of nearly identical porosities (∼61% open volume) are CT scanned at 5.5 μm resolution, and the resulting image stack is reconstructed to produce high-quality finite volume meshes representing the solid and interstitial pore regions, with a conformal mesh at the interface separating these two regions. The resulting mesh is then employed for numerical analysis of thermal transport through fluid-saturated porous sintered beds. Multiple realizations are employed for statistically averaging out the randomness exhibited by the samples under consideration. The effective thermal conductivity and permeability data are compared with analytical models developed for spherical particle beds. The dependence of effective thermal conductivity of sintered samples on the extent of sintering is quantified. The interfacial heat transfer coefficient is compared against a correlation from the literature based on experimental data obtained with spherical particle beds. A modified correlation is proposed to match the results obtained.


Author(s):  
Nihad Dukhan ◽  
Pablo D. Quinones

A one-dimensional heat transfer model for open-cell metal foam is presented. Three aluminum foams having different areas, relative densities, ligament diameters, and number of pores per inch were analyzed. The effective thermal conductivity and the heat transfer increased with the number of pores per inch. The effective thermal conductivity of the foams can be up to four times higher than that of solid aluminum. The resulting improvement in heat transfer can be as high as 50 percent. The maximum heat transfer for the aluminum foams occurs at a pore Reynolds number of 52. The heat transfer, in addition, becomes insensitive to the flow regime for pore Reynolds numbers beyond 200.


2014 ◽  
Vol 102 (3) ◽  
pp. 403-426 ◽  
Author(s):  
Xiao Hu Yang ◽  
Jia Xi Bai ◽  
Hong Bin Yan ◽  
Jiu Jie Kuang ◽  
Tian Jian Lu ◽  
...  

Author(s):  
James D. Playford ◽  
S. Midturi ◽  
S. B. Pidugu

Metallic foams are a new class of ultra-lightweight materials with potential applications in such industries as automobile, aerospace, and energy industries. These materials when realized in product form can serve as efficient heat exchanges, energy absorbers, and thermal protective and hydrogen storage devices. Accurate determination of thermal conductivity and understanding of heat transfer characteristics is important in designing such products incorporating metal foams. The present research characterizes the effective thermal conductivity and heat transfer characteristics of DUOCEL AL 6106-T6 and Stainless Steel 314 open cell foams by experiments at near room temperature conditions. The effective thermal conductivity of these materials has been determined experimentally. Thermal conductivity of metal foams increased with increasing mechanical stress. The effect of porosity on the thermal conductivity of ERG supplied aluminum and NASA-GRC supplied SS 314 are also studied and compared with the published data in literature, however, in our studies systematic dependency of porosity is not observed. Experiments also conducted to quantify forced convective heat transfer characteristics under laminar flow conditions. Heat transfer coefficient increases with increased Reynolds number but results are not conclusive in case of natural convection.


2014 ◽  
Vol 86 ◽  
pp. 95-103 ◽  
Author(s):  
Rhena Wulf ◽  
Miguel A.A. Mendes ◽  
Valeria Skibina ◽  
Ahmad Al-Zoubi ◽  
Dimosthenis Trimis ◽  
...  

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