Library Subscription: Guest
Home Archives Officers Future meetings Assembly for International Heat Transfer Conferences
International Heat Transfer Conference 12

ISSN: 2377-424X (online)
ISSN: 2377-4371 (flashdrive)

An Experimental/ Analytical Technique of Determining Reflection Parameters for Evaluation of Thermal Radiation Energy Exchange between Real Surfaces

Toshiro Makino
Department of Engineering Physics and Mechanics Kyoto University, Japan

Hidenobu Wakabayashi
Department of Engineering Physics and Mechanics Kyoto University, Japan

Abstract

Real surfaces in actual industrial/ natural environments have inhomogeneous microstructure, and reflect the incident thermal radiation specularly in part and diffusely in part. For the heat transfer evaluation, directional characteristics of the radiation reflection should be considered in a minimum detail. A computational technique using the specular reflection component Rs and the perfect-diffuse reflection component Rd of hemispherical reflectance RH is promising for this purpose, but no technique had been developed yet to evaluate the values of Rs and Rd for particular real surfaces. We have investigated directional characteristics of bi-directional reflectance ρ of rough metal surfaces experimentally. In this paper, we extend the work to minimize the labor to measure the ρ distribution, which is a matrix of a large amount of numerical values. A new technique is presented to evaluate Rs and Rd on a basis of the ρ data measured only in the plane of incidence. It is demonstrated that this technique evaluates the values of the two components Rs and Rd of reflectance RH with an inaccuracy within 30% in relative deviation.

Download article Publication Ethics and Malpractice Recommend to my Librarian Bookmark this Page