AN EXPERIMENTAL STUDY ON THE DETERMINATION OF THERMAL CONDUCTIVITY, HEAT CAPACITY AND THERMAL DIFFUSIVITY OF A POROUS METAL FOAM

Year 2017, Volume: 2 Issue: 3, 0 - 0, 01.08.2017

Ozkan Kırec Melda Ozdinc Carpınlıoglu

Abstract

Porous metal foams are novel heat transfer surfaces with the potential use as heat sinks and heat exchangers. In the presented study, thermal characteristics of porous metal foams which are modeled as bulk micro-channel patterns in relevance to the material characteristics are the main topic of discussion given in this paper. An experimental investigation based upon a modeling approach through the measurements of local temperatures along the x-y-z axis of the porous copper foam samples was conducted. A variety of plate type copper foam samples with a size of 150 mm (L), 30 mm (W) and 3 mm, 4 mm, 5 mm (t) with 95 % porosity are tested and physical analysis is presented at heating surface temperatures of TH = 50 ˚C for Ɵ = 10 min.. Effects of the cooling time is also given at TH = 80 ˚C for Ɵ = 10 min. Time dependent thermal views of the samples are taken by usage of thermal imaging camera. Experimental results compared with copper foil reference items are presented to see the various effects of the porous medium on heat transfer. Scanning electron microscopy (SEM) device is used for analyzing the micro-structure of the samples. Local changing of the thermal conductivity, k heat capacity, C and thermal diffusivity, α are calculated as a function of different parameters. The experimental results showed that, k, C and α values of the porous copper foams and copper foil reference items change between 250 W/m.K ≤ k ≤ 517 W/m.K and 40 W/m.K ≤ k ≤ 120 W/m.K, 250 J/K ≤ C ≤ 710 J/K and 255 J/K ≤ C ≤ 715 J/K, 5 mm2/s ≤ α ≤ 42 mm2/s and 0.1 mm2/s ≤ α ≤ 0.8 mm2/s depending on the TH, t and Ɵ

Keywords

Copper Foam, Temperature, Porous Medium, Porosity, Thermal Conductivity, SEM

References

• [1] Xu, H.J.; Qu, Z.G. & Tao, W.Q. (2011b). Thermal Transport Analysis in Parallelplate Channel Filled with Open-celled Metallic Foams. International Communications in Heat and Mass Transfer, Vol.38, No.7, (August 2011), pp. 868- 873, ISSN 0735-1933
• [2] Banhart, J. (2001). Manufacture, characterisation and application of cellular metals and metal foams, Progress in Materials Science, Vol.46, No.6, (2001), pp. 559- 632, ISSN 0079- 6425
• [3] Xu, H.J.; Qu, Z.G. & Tao, W.Q. (2011a). Analytical Solution of Forced Convective Heat Transfer in Tubes Partially Filled with Metallic Foam Using the Two-equation Model. International Journal of Heat and Mass Transfer, Vol. 54, No.17-18, (May 2011), pp. 3846–3855, ISSN 0017-9310
• [4] Xu, H.J.; Qu, Z.G. & Tao, W.Q. (2011b). Thermal Transport Analysis in Parallelplate Channel Filled with Open-celled Metallic Foams. International Communications in Heat and Mass Transfer, Vol.38, No.7, (August 2011), pp. 868- 873, ISSN 0735-1933
• [5] Xu, H.J.; Qu, Z.G.; Lu, T.J.; He, Y.L. & Tao, W.Q. (2011c). Thermal Modeling of Forced Convection in a Parallel Plate Channel Partially Filled with Metallic Foams. Journal of Heat Transfer, Vol.133, No.9, (September 2011), pp. 092603.1-092603.9, ISSN 0022- 1481
• [6] V.V. Calmidi, Transport Phenomena in High Porosity Metal Foams (Ph.D. Thesis), University of Colorado, Boulder, CO, 1998.
• [7] P. Du Plessis, A. Montillet, J. Comiti, J. Legrand, Pressure drop prediction for flow through high porosity metallic foams, Chem. Eng. Sci. 49 (1994) 3545e 3553.
• [8] I. Kurtbas, N. Celik, I. Dinçer, Exergy transfer in a porous rectangular channel, Energy 35 (2010) 451.
• [9] I. Ghosh, How good is open-cell metal foam as heat transfer surface, Trans. ASME: J. Heat Transfer 131 (2009) 101004-1–101004-8.
• [10] M. Kaviany, Principles of Heat Transfer in Porous Media, 2nd Edition, Springer, New York, 1995.
• [11] N. Dukhan, K.C. Chen, Heat transfer measurements in metal foam subjected to constant heat flux, Exp. Therm Fluid Sci. 32 (2007) 624–631.
• [12] N. Dukhan, P.D. Quiñones-Ramos, E. Cruz-Ruiz, M. Vélez-Reyes, E.P. Scott, One dimensional heat transfer analysis in open-cell 10-ppi metal foam, Int. J. Heat Mass Transfer 48 (2005) 5112–5120