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

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

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