ISSN Online: 2377-424X
International Heat Transfer Conference 12
Estimation method of optimum profiles of absorption coefficient for gray analyses in real gas systems enclosed by gray walls
摘要
A new method is proposed to estimate the mean path lengths of radiative energy between emitting gas
elements and the surrounding gray, non-black walls in non-gray gas systems.The new mean path lengths are
substituted to the equation of Patch's effective mean absorption coefficient to estimate the profiles of
equivalent absorption coefficient for gray radiative heat transfer analysis.Using the profiles of absorption
coefficient, gray analysis is shown to give similar results with the exact ones of the corresponding non-gray
analysis.In the present method, the path length is estimated as the sum of mean direct path length between the
gas volume and the surrounding walls and the mean path length the radiative energy emitted by the gas volume
travels after reflected by the walls.The method is applied to two-dimensional model furnace systems, and the
accuracy of the results of gray analyses is shown to be improved from the gray analyses using absorption
coefficient derived by conventional Hottel chart.