radiative transfer


Also found in: Acronyms, Wikipedia.

Radiative transfer

The study of the propagation of energy by radiative processes; it is also called radiation transport. Radiation is one of the three mechanisms by which energy moves from one place to another, the other two being conduction and convection. See Electromagnetic radiation, Heat transfer

The kinds of problems requiring an understanding of radiative transfer can be characterized by looking at meteorology, astronomy, and nuclear reactor design. In meteorology, the energy budget of the atmosphere is determined in large part by energy gained and lost by radiation. In astronomy, almost all that is known about the abundance of elements in space and the structure of stars comes from modeling radiative transfer processes. Since neutrons moving in a reactor obey the same laws as radiation being scattered by atmospheric particles, radiative transfer plays an important part in nuclear reactor design.

Each of these three fields—meteorology, astronomy, and nuclear engineering—concentrates on a different aspect of radiative transfer. In meteorology, situations are studied in which scattering dominates the interaction between radiation and matter; in astronomy, there is more interest in the ways in which radiation and the distribution of electrons in atoms affect each other; and in nuclear engineering, problems relate to complicated, three-dimensional geometry.

Radiative transfer is a complicated process because matter interacts with the radiation. This interaction occurs when the photons that make up radiation exchange energy with matter. These processes can be understood by considering the transfer of visible light through a gas made up of atoms. Similar processes occur when radiation interacts with solid dust particles or when it is transmitted through solids or liquids. See Photon

If a gas is hot, collisions between atoms can convert the kinetic energy of motion to potential energy by raising atoms to an excited state. Emission is the process which releases this energy in the form of photons and cools the gas by converting the kinetic energy of atoms to energy in the form of radiation. The reverse process, absorption, occurs when a photon raises an atom to an excited state, and the energy is converted to kinetic energy in a collision with another atom. Absorption heats the gas by converting energy from radiation to kinetic energy. Occasionally an atom will absorb a photon and reemit another photon of the same energy in a random direction. If the photon is reradiated before the atom undergoes a collision, the photon is said to be scattered. Scattering has no net effect on the temperature of the gas. See Atomic structure and spectra, Scattering of electromagnetic radiation

radiative transfer

[′rād·ē‚ād·iv ′tranz·fər]
(physics)
The propagation of energy by radiative processes, involving emission, absorption, and scattering of electromagnetic radiation. Also known as radiative transport.
References in periodicals archive ?
The reasons for this bias is a combination of both the uncertainty of the solar irradiance measurements and the inaccuracy of the input of the radiative transfer simulations in cloud-free conditions, possibly resulting from inadequate representation of aerosol particles.
The Lee model, however, was evaluated only with the diffusion approximation due to the asymmetry factor defined for this radiative transfer equation.
In this work, using the 3D relativistic hydrocode PLUTO [22] and some in-house (mainly radiative transfer) code (now written both in Mathematica and in C) [23-25], we model [gamma]-ray emissions from hadronic microquasar jets in the [E.sub.[gamma]]-energy range 1.2 GeV [less than or equal to] [E.sub.[gamma]] [less than or equal to] [10.sup.2] - [10.sup.3] TeV.
Travis, "Capabilities and limitations of a current FORTRAN implementation of the T-matrix method for randomly oriented, rotationally symmetric scatterers," Journal of Quantitative Spectroscopy and Radiative Transfer, vol.
Kochanov, "Speed-dependent spectral line profile including line narrowing and mixing," Journal of Quantitative Spectroscopy and Radiative Transfer, vol.
Lin et al., "8 -Fit: A fast and accurate treatment of particle scattering phase functions with weighted singular-value decomposition least-squares fitting," Journal of Quantitative Spectroscopy and Radiative Transfer, vol.
Ozisik, "The use of the Fn method for radiative transfer problems with reflective boundary conditions," Journal of Quantitative Spectroscopy & Radiative Transfer, vol.
The process happens at the speed of light and is a man-made form of 'radiative transfer'.
The radiative transfer equation (RTE) [18, 1] describing the photon propagation in tissue medium.
Three different solvers for the radiative transfer equation have been employed: the discrete ordinate method, the spherical-harmonics method and the optically thin assumption.
libRadtran is a software package for making radiative transfer calculations in Earth's atmosphere, described by Mayer and Kylling (2005).
The first four chapters detail THz light in astrophysical sources: the interstellar medium at THz frequencies, THz radiative transfer, THz continuum emission, and a simple radiative transfer model.