Abstract
Radiant heat transfer consists of the transfer of energy through the electromagnetic waves that are emitted by any material object as a consequence of its temperature. Unlike the other modality of energy transport, i.e., convection and diffusion, radiation does not need a medium, such as air or a metal, to propagate and, in fact, it can move across the void, as it happens with the solar energy reaching the earth surface. Also, radiation is much more dependent on temperature, compared to heat convection and diffusion. Accordingly, radiation is the dominant form of energy transport in furnaces, because of their high temperature, and in cryogenic insulation, because of the vacuum existing between particles. So, for example, gases in a combustion chamber lose more than 90 % of their energy by radiation. In this Section, we will consider the particular form of electromagnetic radiation that is connected to heat transfer, that is thermal radiation. Most energy of this type is in the infra-red region of the electromagnetic spectrum, although some of it is in the visible region, and should not be confused with other forms of electromagnetic radiation, from such as radio waves, X-rays, or gamma rays.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
This relation can be interpreted classically by associating to a photon a fictitious mass m, so that its energy (which is equal to hν, where h is the Planck constant and ν the frequency) is u 1 = mc 2. Then, considering that q = mc, we obtain: u 1 = qc.
- 2.
A simple way to explain why u ∝ T 4 is to consider that in any spatial direction the number of degrees of freedom is proportional to T. For example, if the photons have the same frequency, ν, there will be kT/hν degrees of freedom on any direction. Thus, in 3D, the number of degrees of freedom will be ∝ T 3 and any one of them will have an energy kT/2.
- 3.
Named after Josef Stefan, a Slovenian physicist. σ is also called the Stefan-Boltzmann constant.
- 4.
Consider that: \(\int\nolimits_{0}^{\infty } {\frac{{x^{3} dx}}{{e^{x} - 1}}} = \frac{{\pi^{4} }}{15}\).
- 5.
Named after Gustav Robert Georg Kirchhoff (1824–1887), a German physicist and mathematician.
- 6.
Sometimes it is indicated simply as 12.
- 7.
See for example Bird, Stewart and Lightfoot, Transport Phenomena, Sect. 14.4. The values of the view factor for the most common geometries can be found in Perry, Handbook of Chemical Engineering.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2015 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Mauri, R. (2015). Radiant Heat Transfer. In: Transport Phenomena in Multiphase Flows. Fluid Mechanics and Its Applications, vol 112. Springer, Cham. https://doi.org/10.1007/978-3-319-15793-1_20
Download citation
DOI: https://doi.org/10.1007/978-3-319-15793-1_20
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-15792-4
Online ISBN: 978-3-319-15793-1
eBook Packages: EngineeringEngineering (R0)