The acceleration of the convergence rate is studied for a neutron transport solver to simulate 2-D, 2-energy-group noise problems in frequency domain. Coarse Mesh Finite Difference (CMFD) method compared Diffusion Synthetic Acceleration (DSA) method. Numerical tests are performed using heterogeneous system configurations with different boundary conditions. CMFD scheme leads better rate. results...

Accurate and efficient simulation of remote sensing images is increasingly needed in order to better exploit observations design missions. DART (Discrete Anisotropic Radiative Transfer), developed since 1992 based on the discrete ordinates method (i.e., standard mode DART-FT), one most accurate comprehensive 3D radiative transfer models simulate budget urban natural landscapes. Recently, a new ...

The aim of the paper is to perform 3D radiative transfer calculations in combustion gas mixtures. For this purpose, a parallel modified Discrete Ordinates Method with cell-vertex formulation on unstructured tetrahedral grid proposed for solving Radiative Transfer Equation (RTE) realistic geometries. Several recent formulations weighted-sum-of-gray-gases (WSGG) model are implemented. To reduce f...

Coarse-mesh finite difference (CMFD) method is a widely used numerical acceleration method. However, the stability of CMFD not good for problems with optically thick regions. In this paper, rule named “sign preservation rule” in field heat transfer extended to scheme CMFD. It required that disturbance neutron current positively correlated negative value flux gradient. A necessary condition deri...

An analytical version of the discrete-ordinates method (the ADO method) is used to establish concise and particularly accurate solutions to the viscous-slip and the half-space thermal-creep problems for a binary gas mixture. The kinetic equations used to describe the flow are based on the McCormack model for mixtures. In addition to a computation of the viscous-slip and thermal-slip coefficient...

An analytical version of the discrete-ordinates method (the ADO method) is used to establish a concise and particularly accurate solution to the heat-transfer problem in a plane channel for a binary gas mixture described by the McCormack kinetic model. The solution yields for the general (specular-diffuse) case of Maxwell boundary conditions for each of the two species, the density and temperat...

An analytical version of the discrete-ordinates method (the ADO method) is used with recently established analytical expressions for the rigid-sphere scattering kernels in a study devoted to the flow of a binary gas mixture in a plane channel. In particular, concise and accurate solutions to basic flow problems in a plane channel driven by temperature, pressure, and concentration gradients and ...

An analytical version of the discrete-ordinates method (the ADO method) is used to establish concise and particularly accurate solutions to the problems of Poiseuille flow, thermal-creep flow and diffusion flow for a binary gas mixture confined between parallel walls. The kinetic equations used to describe the flow are based on the McCormack model for mixtures. The analysis yields, for the gene...

An analytical version of the discrete-ordinates method (the ADO method) is used to establish a concise and particularly accurate solution to the temperature-jump problem for a binary gas mixture described by the McCormack kinetic model. The solution yields, in addition to the temperature-jump coefficient for the general (specular–diffuse) case of Maxwell boundary conditions for each of the two ...