On a New Integral Equation Arising in the Theory of Radiative Transfer

1971 ◽  
Vol 20 (4) ◽  
pp. 703-713 ◽  
Author(s):  
Benjamin J. Martin
2002 ◽  
Vol 124 (4) ◽  
pp. 674-684 ◽  
Author(s):  
Zekeriya Altac¸

A high order approximation, the SKN method—a mnemonic for synthetic kernel—is proposed for solving radiative transfer problems in participating medium. The method relies on approximating the integral transfer kernel by a sum of exponential kernels. The radiative integral equation is then reducible to a set of coupled second-order differential equations. The method is tested for one-dimensional plane-parallel participating medium. Three quadrature sets are proposed for the method, and the convergence of the method with the proposed sets is explored. The SKN solutions are compared with the exact, PN, and SN solutions. The SK1 and SK2 approximations using quadrature Set-2 possess the capability of solving radiative transfer problems in optically thin systems.


1985 ◽  
Vol 107 (2) ◽  
pp. 478-481 ◽  
Author(s):  
F. H. Azad

Radiative transfer in a semitransparent medium is treated using the differential approximation. Boundary conditions are formulated to accommodate direction-dependent reflection and refraction at a dielectric interfaces. The approximate results are compared to numerical solution of the exact integral equation. Also, a modification based on the exact formulation of the integrated intensity at the interface is presented that significantly improves the accuracy of the differential approximation in the optically thin regimes.


1966 ◽  
Vol 62 (2) ◽  
pp. 249-261 ◽  
Author(s):  
R. F. Millar

AbstractThe problem of diffraction of a plane wave by a semi-infinite grating of iso-tropic scatterers leads to the consideration of a non-linear integral equation. This bears a resemblance to Chandrasekhar's integral equation which arises in the study of radiative transfer through a semi-infinite atmosphere. It is shown that methods which have been used with success to solve Chandrasekhar's equation are equally useful here. The solution to the non-linear equation satisfies a more simple functional equation which may be solved by factoring (in the Wiener-Hopf sense) a given function. Subject to certain additional conditions which are dictated by physical considerations, a solution is obtained which is the unique admissible solution of the non-linear integral equation. The factors and solution are found explicitly for the case which corresponds to closely spaced scatterers.


1990 ◽  
Vol 8 (4) ◽  
pp. 741-751 ◽  
Author(s):  
G. C. Pomraning

A formulation of radiative transfer is discussed describing energy flow in a turbulent mixture in the vicinity of a Rayleigh–Taylor unstable interface, as might be extant in an ICF pellet. Included in this discussion are (1) the method of smoothing and the Liouville master equation approaches in the case of Markovian statistics as the description of the fluid mixing, (2) the use of asymptotics to derive various limiting descriptions of the Markov model, (3) the use of the theory of alternating renewal processes to obtain an integral equation formulation for non-Markovian statistics, and (4) the reduction of this non-Markovian integral formulation to integro-differential equations of the generic transport form, with statistical effects represented by pseudoscattering terms.


Author(s):  
Xiaodong Lu ◽  
Pei-Feng Hsu ◽  
John C. Chai

The transient radiative transfer process is studied with a finite volume method (FVM) and an integral equation (IE) model. Propagation of a short light pulse in the three-dimensional absorbing and isotropic scattering media is considered. Collimated irradiation enters at one side of the rectangular medium. The other five boundaries are cold and black, nonparticipating surfaces. The spatial and temporal distributions of the integrated intensity and radiative flux are obtained.


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