Properties of Absorbing and Emitting Media

2015 ◽  
pp. 475-524
Keyword(s):  
Emitting Media

Two-Dimensional Radiation in Absorbing-Emitting Media Using the P-N Approximation

1983 ◽  
Vol 105 (2) ◽  
pp. 333-340 ◽  
Author(s):  
A. C. Ratzel ◽  
J. R. Howell
Keyword(s):  
Separation Of Variables ◽  
Second Order ◽  
Radiative Energy ◽  
Two Dimensional ◽  
Differential Approximation ◽  
Relaxation Methods ◽  
Emissive Power ◽  
Diffusion Solution ◽  
Emitting Media ◽  
Successive Over Relaxation

Radiative energy transfer in a gray absorbing and emitting medium is considered in a two-dimensional rectangular enclosure using the P-N differential approximation. The two-dimensional moment of intensity partial differential equations (PDE’s) are combined to yield a single second-order PDE for the P-1 approximation and four coupled second-order PDE’s for the P-3 approximation. P-1 approximation results are obtained from separation of variables solutions, and P-3 results are obtained numerically using successive-over-relaxation methods. The P-N approximation results are compared with numerical Hottel zone results and with results from an approximation method developed by Modest. The studies show that the P-3 approximation can be used to predict emissive power distributions and heat transfer rates in two-dimensional media with opacities of unity or greater. The P-1 approximation is identical to the diffusion solution and is thus applicable only if the medium is optically dense.

Design of selective emitting media within a cylindrical tube for conversion of wasted heat energy to electrical energy

2011 ◽  
Vol 109 (1) ◽  
pp. 013112
Author(s):  
P. Starvaggi ◽  
M. Hoffman ◽  
C. B. Clemons ◽  
G. W. Young
Keyword(s):  
Cylindrical Tube ◽  
Electrical Energy ◽  
Heat Energy ◽  
Emitting Media ◽  
Wasted Heat

scholarly journals Testing the photoionization models of powerful radio galaxies: mixed line-emitting media in 3C 321

2000 ◽  
Vol 317 (4) ◽  
pp. 922-936 ◽  
Author(s):  
T. G. Robinson ◽  
C. N. Tadhunter ◽  
D. J. Axon ◽  
A. Robinson
Keyword(s):  
Radio Galaxies ◽  
Powerful Radio ◽  
Emitting Media ◽  
Mixed Line

Band Radiation within Diffuse-Walled Enclosures—Part II: An Approximate Method Applied to Simple Enclosures

1979 ◽  
Vol 101 (1) ◽  
pp. 85-89 ◽  
Author(s):  
D. A. Nelson
Keyword(s):  
Approximate Method ◽  
High Accuracy ◽  
Principal Feature ◽  
Band Absorption ◽  
Emitting Media ◽  
Low Order

An asymptotically exact approximate method of analysis for band radiation has been applied to some simple enclosures. The principal feature of the method is direct utilization of band absorption formulations for absorbing-emitting media. The procedure is shown to be capable of arbitrarily high accuracy and to have very acceptable errors for low order approximations.

A Parametric Case Study in Radiative Heat Transfer Using the Reverse Monte-Carlo Ray-Tracing With Full-Spectrum k-Distribution Method

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
Xiaojing Sun ◽  
Philip J. Smith
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Ray Tracing ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Reverse Monte Carlo ◽  
Full Spectrum ◽  
Distribution Method ◽  
Mesh Resolution ◽  
Emitting Media

A combined method of reverse Monte-Carlo ray-tracing with full-spectrum k-distribution (FSK) for computing the radiative heat transfer is applied to an extreme nonhomogeneous case (both temperature and gas mixture composition vary with positions) with an absorbing, emitting media. The parameter studies of the scaled FSK (FSSK) and correlated FSK (FSCK) methods for the case, such as g point resolution, mesh resolution, reference states, and integration quadratures, are carried out. The results from the FSSK and FSCK are only affected by the chosen reference states and are not sensitive to other parameters.

Transient Radiation Element Method for Three-Dimensional Scattering, Absorbing, and Emitting Media

2001 ◽  
Author(s):  
Zhixiong Guo ◽  
Sunil Kumar ◽  
Shigenao Maruyama
Keyword(s):  
Radiative Transfer ◽  
Transient Analysis ◽  
Radiative Heat ◽  
Three Dimensional ◽  
The Media ◽  
Emitting Media ◽  
Inhomogeneous Properties ◽  
First Time ◽  
Good Agreement ◽  
Element Method

Abstract In this study transient radiative heat transfer is investigated in scattering, absorbing, and emitting media. The radiation element method is formulated for the first time to solve the transient radiative transfer equation in 3-D geometries. The sensitivity and accuracy of the method are examined. A good agreement of temporal transmittance predicted by the present method and Monte Carlo method is found. The characteristics of transient analysis are investigated via various problems of radiative transfer in inhomogeneous cubes. It is found that the transmitted signals are strongly affected by the inhomogeneous properties of the media through which the radiation has passed. In the position where the radiation travels a larger optical thickness, the broadening of the transmitted pulse width is more obvious and the magnitude of the transmittance is smaller.

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