Exact solution of the problem of diffuse reflection for a combination of Rayleigh and isotropic scattering

1979 ◽  
Vol 63 (1) ◽  
pp. 171-175
Author(s):  
Rabindra Nath Das
Keyword(s):  
Exact Solution ◽  
Diffuse Reflection ◽  
Isotropic Scattering

scholarly journals An exact solution of linearized flow of an emitting, absorbing and scattering grey gas

1971 ◽  
Vol 45 (4) ◽  
pp. 673-699 ◽  
Author(s):  
Ping Cheng ◽  
A. Leonard
Keyword(s):  
Integral Equation ◽  
Exact Solution ◽  
Transport Theory ◽  
Neutron Transport ◽  
Separation Of Variables ◽  
Closed Form Solution ◽  
Strong Shock ◽  
Form Solution ◽  
Isotropic Scattering ◽  
Differential Approximation

The governing equations for the problem of linearized flow through a normal shock wave in an emitting, absorbing, and scattering grey gas are reduced to two linear coupled integro-differential equations. By separation of variables, these equations are further reduced to an integral equation similar to that which arises in neutron-transport theory. It is shown that this integral equation admits both regular (associated with discrete eigenfunctions) and singular (associated with continuum eigenfunctions) solutions to form a complete set. The exact closed-form solution is obtained by superposition of these eigen-functions. If the gas downstream of a strong shock is absorption–emission dominated, the discrete mode of the solution disappears downstream. The effects of isotropic scattering are discussed. Quantitative comparison between the numerical results based on the exact solution and on the differential approximation are presented.

scholarly journals On the property of ”statistical identity” of solutions to some classical problems of the radiative transfer theory

2021 ◽  
pp. 502-508
Author(s):  
H. V. Pikichyan
Keyword(s):  
Radiative Transfer ◽  
Diffusion Process ◽  
Diffuse Reflection ◽  
Isotropic Scattering ◽  
Probabilistic Interpretation ◽  
Temporal Dependence ◽  
Absorbing Medium ◽  
Direct Transformation ◽  
Nonhomogeneous Media ◽  
Random Events

A probabilistic interpretation of the classical solution of the diffuse reflection problem (DRP) of radiation from a semi-infinite homogeneous scattering-absorbing medium on the language of random events in the simple case of monochromatic and isotropic scattering is constructed. A certain property of the so-called ”statistical identity” is specially defined. By using these two circumstances, it is possible to construct a simple symbolic scheme for the direct transformation of the solution mentioned above in the particular case of DRP into solutions to more general cases of DRP, which taking into account the anisotropy and incoherence of scattering, as well as the temporal dependence of the task on the act of absorption. Moreover, some generalization of the primary scheme makes it possible to directly obtain solutions of the DRP also for nonhomogeneous media and for general case of time dependence (on absorption acts and free flights between them) for the quanta diffusion process. At the same time, both the well-known results of the DRP decisions and some new ones were obtained.

Exact solution of a four-site crystal model for an intermediate-valence system

1986 ◽  
Vol 47 (6) ◽  
pp. 1029-1034 ◽  
Author(s):  
J.C. Parlebas ◽  
R.H. Victora ◽  
L.M. Falicov
Keyword(s):  
Exact Solution ◽  
Intermediate Valence ◽  
Crystal Model
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