Results 191 to 200 of about 55,042 (216)

Acceleration schemes for the discrete ordinates method

Journal of Thermophysics and Heat Transfer, 1996
Discrete ordinates (DO) methods have been developed to solve the multidimensional radiative transport equation (RTE) for applications including combustion processes and other combined-mode heat transfer cases. The convergence of DO methods is known to degrade for optical thicknesses greater than unity, which occur for example in a flame.
V. A. Fiveland, J. P. Jessee
openaire   +1 more source

Numerical analysis of discrete ordinate methods

Journal of Computational Physics, 1968
Abstract It is shown that the DSN equations for spherical nonscattering time-dependent systems can be put in matrix form, and that one can then apply well-known theorems to obtain criteria for stability and monotonicity of the difference operator.
openaire   +2 more sources

A Variational Synthesis Nodal Discrete Ordinates Method

Nuclear Science and Engineering, 1999
A self-consistent nodal approximation method for computing discrete ordinates neutron flux distributions has been developed from a variational functional for neutron transport theory. The advantage of the new nodal method formulation is that it is self-consistent in its definition of the homogenized nodal parameters, the construction of the global ...
J. A. Favorite, W. M. Stacey
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Particular solutions for the discrete-ordinates method

Journal of Quantitative Spectroscopy and Radiative Transfer, 2000
Abstract A full-range orthogonality relation is developed and used to construct the infinite-medium Green’s function for a general form of the discrete-ordinates approximation to the transport equation in plane geometry. The Green’s function is then used to define a particular solution that is required in the solution of inhomogeneous versions of the
L.B Barichello, R.D.M Garcia, C.E Siewert   +2 more
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Ray Effects in Discrete Ordinates Equations

Nuclear Science and Engineering, 1968
The nature of anomalous computational effects due to the discretization of the angular variable in transport theory discrete ordinates approximations is described and analyzed.
openaire   +1 more source

Sputtering Calculations with the Discrete-Ordinates Method

Nuclear Science and Engineering, 1978
The purpose of this work is to investigate the applicability of the discrete-ordinates (S/sub N/) method to light ion sputtering problems. In particlar, the neutral particle discrete-ordinates computer code, ANISN, is used to calculate sputtering yields. No modifications to this code are necessary to treat charged particle transport.
Hoffman, T. J., Dodds Jr., H. L., Robinson, M.T., Holmes, D.K.   +3 more
openaire   +1 more source

The discrete-ordinate method in diffusive regimes

Transport Theory and Statistical Physics, 1991
Abstract In highly scattering regimes, the transport equation has a limit in which the leading behavior of its solution is determined by the solution of a diffusion equation. A boundary layer with a thickness of a few mean free paths usually forms between the domain boundary and the interior region, through which the given transport boundary conditions
Shi Jin, David Levermore
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Analysis of discrete ordinates method with even parity formulation

Journal of Thermophysics and Heat Transfer, 1996
The even parity formulation (EPF) of the discrete ordinates method (DOM) is used to simulate radiative heat transfer in two-dimensional enclosures containing an absorbing-emitting and scattering medium. The discrete ordinates equations for the EPF are second-order differential equations and they are spatially discretized using a second-order central ...
J. Liu, H. Shang, Y. Chen, T. Wang
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Boundary conditions for the discrete ordinate equations

Annals of Nuclear Energy, 1993
Abstract It is known that the planar geometry spherical harmonic ( P N − 1 ) equations associated with linear transport problems are equivalent to the planar geometry discrete ordinate ( S N ) equations of one higher order, if Gauss-Legendre quadrature is used.
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A New Derivation of Discrete Ordinate Approximations

Nuclear Science and Engineering, 1968
It is shown that the idea of space-angle synthesis may be used to provide a new framework for the derivation of discrete ordinate methods.
openaire   +1 more source