ABSTRACT
This chapter discusses spectrum thermal radiation intensity and emissive power for a blackbody as well as a real surface at elevated temperatures; and surface radiation properties such as spectral emissivity and absorptivity for real-surface radiation. It illustrates how to obtain the total emissivity or absorptivity from the fraction method; how to perform energy balance from a flat surface including radiation and convection; and solar and atmospheric radiation problems. The chapter provides fundamental thermal radiation and surface properties that are useful for many engineering applications such as surface radiators. In addition to emission, a surface can reflect, absorb, or transmit any oncoming radiation energy (irradiation). Through the thermal and photovoltaic process, solar radiation is important for the design of solar collectors, air-conditioning systems for buildings and vehicles, temperature control systems for spacecrafts, and photocells for electricity. The magnitude spectral and directional distributions of solar flux change significantly as solar radiation passes through the Earth’s atmosphere.
