Radiation Heat Transfer
This chapter explores the fundamental concepts of radiation heat transfer, including the interaction of radiation with materials, the key properties such as emissivity, absorptivity, and reflectivity, and essential laws such as the Stefan–Boltzmann law. It also discusses practical applications, view factors, and methods for calculating radiative exchange between surfaces. The chapter concludes by highlighting the importance of radiation shields in thermal management.
Sections
Navigate through the learning materials and practice exercises.
What we have learnt
- Thermal radiation is energy emitted by matter due to its temperature and requires no medium for its travel.
- Key radiative properties include emissivity, absorptivity, reflectivity, and transmissivity, which can be described using specific equations.
- Radiation heat transfer calculations consider surface emissivity, geometry, shape factors, and can be managed using methods like the radiosity method.
Key Concepts
- -- Emissivity (ε)
- The ratio of radiation emitted by a surface to that by a blackbody at the same temperature.
- -- Stefan–Boltzmann Law
- A law describing the power radiated from a blackbody in terms of its temperature, represented as Eb = σT4.
- -- View Factors (Configuration Factors)
- The fraction of radiation leaving one surface that strikes a second surface, crucial for calculating radiation exchange.
- -- Blackbody
- An ideal emitter and absorber of radiation with emissivity equal to 1.
- -- Radiosity
- The total energy leaving a surface, which includes both emitted and reflected energy.
Additional Learning Materials
Supplementary resources to enhance your learning experience.