Determination of the local angular coefficient for a cylindrical surface

In the calculation of heat transfer by radiation from an object it is necessary to determine the angle coefficient between a cylindrical surface and the surface of the object, which can be reduced to determining the angle coefficient between a cylindrical surface and a small surface element. In this paper, for the case when the normal to the center of the surface element is parallel to the cylinder axis, an expression for calculating the local angle coefficient is derived by integrating the fundamental equation. Graphs of the local angle coefficient as a function of cylinder height and distance from the surface element are given, and the limiting value of this coefficient as cylinder height becomes infinite is computed.