Specialty Grand Challenge for Heat Transfer and Thermal Power

Abstract

It is known that the study of the processes of heat generation and propagation, as well as its transformation into other types of energy, led to the discovery of fundamental physical laws. We should remember, first of all, the laws of thermal radiation, the discovery of which just over a century ago radically changed physics as a science and became the basis of incredible technical advances. The revolution in theoretical physics has greatly accelerated research in heat transfer and various applications, especially in thermal engineering. Textbooks usually distinguish three ways of heat transfer: conduction, convection, and thermal radiation. However, attempts to solve real problems show that we are usually dealing with combined heat transfer, when different modes of heat transfer interact with each other. In my opinion, thermal radiation is closer to fundamental science and appears to be a more global phenomenon than other modes of heat transfer. It is not even the fact that life on our planet exists because of thermal radiation from the Sun, and this radiation extends 150million kilometers to reach the Earth. Contrary to popular belief, thermal radiation turns out to be important at any temperature and at any distance, and its spectrum includes the microwave range used in remote sensing of the ocean surface. This explains why we focus on radiative and combined heat transfer, and the variety of problems involved is so great. The research topics under consideration are mainly related to various problems of radiation transfer in semitransparent scattering media. Such media are, for example, gases or liquids with suspended particles, as well as various dispersed materials and solids with microcracks or bubbles. Natural objects of study include the Earth’s atmosphere and ocean, snow and ice, powders or dust and ordinary sand, and even biological tissues with optically heterogeneous living cells. In thermal engineering these are combustion products containing soot and fly ash particles, porous ceramics and heat-shielding materials, particles in thermochemical reactors and melt droplets from a possible severe nuclear reactor accident. A far from complete set of given examples leaves no doubt about the practical importance of studying radiation propagation in scattering media. Therefore, our editorial team was formed mainly from researchers working in the field of radiative and combined heat transfer in disperse systems. The classical theory of radiative transfer in such media is based on the integrodifferential equation, which was independently derived early last century by Orest Khvolson and Subrahmanyan Chandrasekhar in connection with the study of radiative transfer in stellar photospheres (Chandrasekhar 1960; Rosenberg 1977). A modern systematic account of the theory of radiative heat transfer can be found in textbooks by Howell et al. (2021) and Modest and Mazumder (2021), and an engineering approach tomodeling radiative and combined heat transfer in disperse systems is discussed in Dombrovsky and Baillis (2010). The radiative transfer equation in a scattering medium does not take into account the wave nature of electromagnetic radiation, which appears most strongly when the radiation is scattered by particles Edited and reviewed by: Xianguo Li, University of Waterloo, Canada