What is Radiation heat transfer: Definition and 20 Discussions

Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. Particle motion results in charge-acceleration or dipole oscillation which produces electromagnetic radiation.
Infrared radiation emitted by animals (detectable with an infrared camera) and cosmic microwave background radiation are examples of thermal radiation.
If a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium, the radiation is called blackbody radiation. Planck's law describes the spectrum of blackbody radiation, which depends solely on the object's temperature. Wien's displacement law determines the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the radiant intensity.Thermal radiation is also one of the fundamental mechanisms of heat transfer.

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  1. FEAnalyst

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  2. A

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  3. FEAnalyst

    Radiation heat transfer between parallel plates

    Hi, the approximate (not accounting for plate size and separation distance) formula for heat flux exchanged via radiation between two parallel plates is: $$q=\frac{\sigma (T_{1}^{4}-T_{2}^{4})}{\frac{1}{\varepsilon_{1}}+\frac{1}{\varepsilon_{2}}-1}$$ where: ##\sigma## - Stefan-Boltzmann...
  4. V

    Radiation heat transfer in channel flow

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  5. imselva

    Radiation heat transfer using 12 heat sources

    The intensity is proportional to the square of the distance between the source and the body and also depends on the angle of incident. I = The intensity at 0° (Assuming I = some constant) then I0 = I cos(Theta) Theta = the angle of incidence. I want to solve this using trignomentry. Is it...
  6. imselva

    What is the Equilibrium State in Radiation Heat Transfer?

    I have two bodies, one at a higher temperature say 1000°C (Body A) and the other is at 22°C (Body B). Body A emits Radiation (Surface to Surface interaction). The temperature of Body A is maintained by a constant supply of Energy. The Body B will absorb the Radiation Energy from Body A, and its...
  7. B

    Radiant heat transfer and specific heat

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  8. R

    Heat transfer through AL shield by radiation & convection

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  9. A

    Please help me with this doubt about radiant heat transfer

    My textbook says that net rate of heat transfer due to radiation is εσA(T^4-To^4) but i couldn't understand it. Rate of emission is εσAT^4 and rate of absorption is aσATo^4 so net rate of heat transfer must be εσAT^4-aσATo^4(where T is the temperature of body and To is the temperature of...
  10. G

    Stability of radiative heat transfer

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  11. Dong Aleta

    Radiation to a small object from surroundings

    In the energy balance of a system where a small object at T1 enclosed in a body at T2 given by the Stefan-Boltzmann equation q = A1ε1σT14 - A1α12σT24 shouldn't it be a differential equation since the small body could be absorbing/releasing sufficient net energy from the enclosing body that...
  12. I

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  13. L

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  14. P

    Radiation heat transfer - mistake in attached solution?

    I attached the problem of interest (probably the only part you guys need to see is the equations at the bottom). My answers are off by a magnitude of 10 compared to the solutions. (copy and pasted it below since the pic is a little hard to see at the bottom) q = σε f*A(T^4 − Ts^4 ) = 5.67...
  15. E

    Two questions about thermal radiation heat transfer

    Hi guys, could you concretely explain me (also with a simple example) the difference between blackbody emissive power (sometimes found as e'λb) and blackbody radiation intensity (i^{'}_{λb})? and which the difference between a diffuse surface and a surface that follows the Lambert law? Thank...
  16. Z

    Radiation heat transfer between air or wall

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  17. D

    View Factor in radiation heat transfer

    Hi can anyone temme how to calculate view factor between two spheres.
  18. D

    Radiation heat transfer (V-shaped and rect cavity)

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  19. W

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  20. Q_Goest

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    I'm reviewing a letter regarding the sheilding of an object using a superconducting magnet as is commonly found in MRI machines. The claim is that the magnetic field created by superconducting windings (wire which is carrying a current and thus creating a magnetic field) and wrapped around an...
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