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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Theoretical and experimental evaluation of the radiative properties of a dispersed particulate medium

Get access (open in a dialog) DOI: 10.1615/IHTC12.4880
6 pages

摘要

Heat buildup in construction materials may be significantly reduced by the incorporation of scattering particles. Scattering particles of two material compositions, and three particle size and volume percent ranges were added to a pigmented polymeric material to measure the change in diffuse using an Integrating Sphere Spectrophotometer. In addition, the resulting change in temperature rise due to the incorporation of the particles was determined using ASTM D4803The radiative heat transfer was then modeled using a Mie Scattering Fortran program for the particles of smallest size (1-20 um) and Large Sphere Scattering theory was applied for particles of largest size (88-106 um). The scattering particles were found to alter the diffuse reflectance of the material, depending on the refractive index, volume percent, and particle size combination. For the Mie Scattering case, greater values of relative refractive index and smaller particle sizes provided higher values of diffuse reflectance and lower temperatures. Similarly, for Large Specularly reflecting spheres, higher values of diffuse reflectance and lower temperatures were found for spheres with a higher refractive index. However, Large Diffusely reflecting spheres provide lower diffuse reflectance values and higher temperatures.