Hyperbolicity and critical points in two - moment approximate radiative transfer
نویسندگان
چکیده
We present numerical calculations of spherically symmetric radiative transport using a two-moment (P-1) method with a two-dimensional non-linear closure on the Eddington factor. The stationary state solutions contain a critical point. We demonstrate that the two-moment equations with a non-linear closure are well behaved. The solutions are physically acceptable , regular and accurate.
منابع مشابه
Relativistic moment equations in media with strong velocity gradients
The one-dimensional stationary PSTF moment equations for radiative transfer in relativistically differentially moving media are examined. It is found that the equations can have two different types of critical points. In regions of strong velocity gradients, solutions might have pathological behavior around such critical points. The moment method may therefore yield unphysical solutions for the...
متن کاملHyperbolic character of the angular moment equations of radiative transfer and numerical methods
We study the mathematical character of the angular moment equations of radiative transfer in spherical symmetry and conclude that the system is hyperbolic for general forms of the closure relation found in the literature. Hyperbolicity and causality preservation lead to mathematical conditions allowing to establish a useful characterization of the closure relations. We apply numerical methods s...
متن کاملANALYSIS OF COMBINED CONDUCTION AND RADIATION HEAT TRANSFER IN A RECTANGULAR FURNACE INCLUDING TWO FLAMES
Abstract: The present study deals the theoretical modeling aspects of coupled conductive and radiative heat transfer in the presence of absorbing, emitting and scattering gray medium within two-dimensional square furnace including two flames. The gray radiative medium is bounded by isothermal walls which are considered to be opaque, diffuse and gray. The well known discrete ordinate method (DOM...
متن کاملComputational Study of Radiative and Convective Heat Transfer in a Cylindrical Combustion Chamber
In this paper, the effect of cold air on the fluid flow inside the cylindrical combustion chamber and its wall temperature distribution have been studied computationally, taking into account the effect of radiative heat transfer from hot gases. The results have been compared with the case that radiative heat transfer was neglected. It is observed that the reattachment length increases when incr...
متن کاملStable states in the radiant heat transfer of the near field for two parallel slabs
In this paper, we study the dynamics of the radiative heat transfer of between two slabs. In these systems, depending on the type of slabs and the thermal interaction they have with their surroundings, they can have one or several stable states in the phase space. It can be seen that in these systems, quantities such as distance and thickness affect the states of these systems. We show that the...
متن کامل