scholarly journals REZONE-A PROPOSAL FOR ACCOMPLISHING REZONING IN TWO-DIMENSIONAL LAGRANGIAN HYDRODYNAMICS PROBLEMS

1965 ◽  
Author(s):  
P Browne
Keyword(s):  
Two Dimensional ◽  
Lagrangian Hydrodynamics

The Construction of a Conservative Radiation Hydrodynamics Algorithm in Two-Dimensional Spherical Geometry

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Zhiwei Lin ◽  
Shaoen Jiang ◽  
Lu Zhang
Keyword(s):  
Radiation Transport ◽  
Spherical Geometry ◽  
Artificial Viscosity ◽  
Radiation Hydrodynamics ◽  
Two Dimensional ◽  
Hydrodynamic Equations ◽  
Spherical Coordinates ◽  
Spatial Control ◽  
Lagrangian Hydrodynamics ◽  
Control Volumes

Abstract This paper presents the construction of a conservative radiation hydrodynamics algorithm in two-dimensional (2D) spherical geometry. First, we discretize the radiation transport equation (RTE) in that geometry. The discretization preserves the conservation of photons by integrating the original RTE in 2D spherical coordinates over both angular and spatial control volumes. Some numerical results are provided to verify the discretization for both optically thin and thick circumstances. Second, we formulate the staggered Lagrangian hydrodynamics in that geometry. The formulation preserves the conservation of mass, momentum, and energy by integrating the original hydrodynamic equations in 2D spherical coordinates over their respective control volumes. The original edge-centered artificial viscosity in 2D cylindrical geometry is also extended to be capable of capturing shock waves in 2D spherical geometry. Several 2D benchmark cases are provided to verify the scheme. The subsequent construction of the conservative radiation hydrodynamics algorithm is accomplished by the combination of the staggered Lagrangian hydrodynamics scheme and the solution of the RTE in 2D spherical geometry. Several 2D problems are calculated to verify our radiation hydrodynamics algorithm at the end.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Sign in / Sign up

Export Citation Format

Share Document