Radiation hydrodynamics with many spectral lines

• Verfasst von: Baschek, Bodo [VerfasserIn]
• Verfasst von: Grueber, C. [VerfasserIn]
• Verfasst von: Waldenfels, Wilhelm von [VerfasserIn]
• Verfasst von: Wehrse, Rainer [VerfasserIn]
• Titel: Radiation hydrodynamics with many spectral lines
• Titelzusatz: analytical expressions for a differentially moving slab.
• Verf.angabe: B. Baschek, C. Grueber, W. von Waldenfels, R. Wehrse
• Jahr: 1997
• Umfang: 9 S.
• Fussnoten: Gesehen am 17.04.2023
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 1997
• Band/Heft Quelle: 320(1997), Seite 920-928
• ISSN Quelle: 1432-0746
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: HYDRODYNAMICS
• Sach-SW: METHODS: ANALYTICAL
• Sach-SW: RADIATIVE TRANSFER
• K10plus-PPN: 1842786105

Abstract

An analytical solution of the comoving frame radiative transfer equation for a differentially moving slab is obtained and written in terms of the wavelength-integrated extinction coefficient ψ, the spectral thickness. It is shown that ψ is much smoother than the extinction coefficient χ(λ) itself and that it can be well approximated e.g. by a simple piecewise linear function. Compared to conventional algorithms it allows speed-ups of factors >=10^5^ in the calculation of wavelength-integrated quantities such as e.g. the total flux, the radiative force, or the energy balance with an accuracy of <=1%. The total number of lines which can be taken into account is essentially unlimited. A simple expression for the total flux in the diffusion limit is derived and the dependencies on the velocity gradient are discussed.