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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Volumetric Heat Transfer Determination for Forced Convection of Air through Alumina (Al2O3) Foam

Get access (open in a dialog) DOI: 10.1615/IHTC15.fcv.008769
pages 3115-3128

Sinopsis

Open cell ceramic foams are used in metal purification as filter because of their high temperature heat resistance. Since it is a difficult task to execute experiments for molten metal flow, the foam characteristics such as volumetric heat transfer coefficient and permeability can be determined for flow of other fluids of similar flow characteristics. The purpose of this study is to experimentally determine volumetric heat transfer coefficient (hv) and permeability (K) of alumina foams with air as a flowing fluid in a two phase flow system. A new testing facility in the form of a wind tunnel is designed, which is capable of conducting steady state and transient forced convection experiments for air temperature up to 400°C using a resistance coil air heater. Design of the testing facility can accommodate up to four sided heating of cuboid shape foams using copper heating plates. Alumina foams tested for this study are having 10 and 30 pores per inch (PPI). For this study only steady state experiments are conducted for one and two sided heating of alumina foam. Effective thermal conductivity (ke) of open cell foams is an important parameter that influences the value of hv. Hence various existing models are used to determine ke for comparative data analysis of one and two sided heating of samples. Additional correlations for dispersion conductivity (kd) are taken from available literature. Experiments are conducted for channel Reynolds number ranging from 3300 to 33000 and heat supplied to each copper heating plate is varied from 4 to 10 kW/m2. Energy equations for both solid and fluid are coupled together through volumetric heat transfer coefficient and they are solved separately using implicit method. The results are implemented in the form of volumetric Nusselt number Nuf, channel Reynolds number ReH and wall Nusselt number Nu by curve fitting the numerical results with experimental data.