Abstract

The local effective emissivity for a point on the interior surface of a diffusely reflecting blackbody cone obeys an integral equation. A new analytic approximate solution of the integral equation is presented. This approximation is very good for interior portions of narrow cones where the effective emissivity is very close to unity. Another approximation of Kelley is better near the mouth of a narrow cone. Either approximation works for wide angle cones. The new approximation is modified to give a quantitative estimate of the effects of a temperature gradient along the side of the cone.

© 1979 Optical Society of America

An Equation for the Local Thermal Emissivity at the Vertex of a Diffuse Conical or V-Groove Cavity

Francis J. Kelly
Appl. Opt. 5(6) 925-927 (1966)

Emissivities of diffuse cavities: Isothermal and nonisothermal cones and cylinders

R. E. Bedford and C. K. Ma
J. Opt. Soc. Am. 64(3) 339-349 (1974)

Radiant Emission Characteristics of a Nonisothermal Spherical Cavity

P. Campanaro and T. Ricolfi
Appl. Opt. 5(8) 1271-1273 (1966)

Emissivities of diffuse cavities. 4: Isothermal and nonisothermal cylindro-inner-cones

Ronald E. Bedford, C. K. Ma, Zaixiang Chu, Yuxing Sun, and Shouren Chen
Appl. Opt. 24(18) 2971-2980 (1985)

Spectral effective emissivities of nonisothermal cavities calculated by the Monte Carlo method

V. I. Sapritsky and A. V. Prokhorov
Appl. Opt. 34(25) 5645-5652 (1995)