Pub Date : 2022-04-26DOI: 10.3389/fther.2022.862070
L. Dombrovsky
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
{"title":"Specialty Grand Challenge for Heat Transfer and Thermal Power","authors":"L. Dombrovsky","doi":"10.3389/fther.2022.862070","DOIUrl":"https://doi.org/10.3389/fther.2022.862070","url":null,"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","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46926059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-12DOI: 10.3389/fther.2022.861882
Jin-Kuk Kim
A new design methodology for the process synthesis of electrified energy systems, e-site analysis, for the application of process industries, is presented, which allows the systematic selection of electrified units in process levels and provides design guidelines for the configuration of site utility systems. Different characteristics associated with the use of power-to-heat technologies for thermal heating, compared with traditional heat supply from the combustion of fossil fuels, are discussed in the context of process design and site-wide utility management. The new design framework is developed for the transformation of conventional steam-based utility systems to electricity-based ones. The applicability of the proposed design method and its benefits from carbon-neutral energy generation is demonstrated with a case study, which clearly illustrates the impact of electrification on the design and operation of site utility systems in process industries.
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Pub Date : 2022-01-03DOI: 10.3389/fther.2021.807083
L. Dombrovsky
The most interesting, but insufficiently known results obtained by the author in modeling laser-induced hyperthermia of human tumors are discussed. It is important that the traditional equation for the local bio-heat transfer does not work in superficial layers of the body. It is shown also that the classical Arrhenius law is not applicable to living tissues because of the tissue regeneration due to oxygen supplied by the arterial blood. The latter is one of the main reasons of the suggested strategy of laser heating of tumors in the therapeutic window of semitransparency when the tumor asphyxiation is considered as one of important weapons against the cancer. The other advantages of this advanced strategy of a soft thermal treatment (in few of sessions), which is painless for patients, are discussed as well. Some features of modeling various heat transfer modes are also considered. The best choice between the simplest differential models for the radiative transfer calculations is dependent of the particular problem statement. The known finite-difference or finite element algorithms can be preferable in solving transient heat transfer problems. As a rule, it depends on the shape of the computational region. It is expected that this paper will help the colleagues to overcome some typical weaknesses of computational modeling of infrared photothermal treatment of superficial tumors.
{"title":"Laser-Induced Thermal Treatment of Superficial Human Tumors: An Advanced Heating Strategy and Non-Arrhenius Law for Living Tissues","authors":"L. Dombrovsky","doi":"10.3389/fther.2021.807083","DOIUrl":"https://doi.org/10.3389/fther.2021.807083","url":null,"abstract":"The most interesting, but insufficiently known results obtained by the author in modeling laser-induced hyperthermia of human tumors are discussed. It is important that the traditional equation for the local bio-heat transfer does not work in superficial layers of the body. It is shown also that the classical Arrhenius law is not applicable to living tissues because of the tissue regeneration due to oxygen supplied by the arterial blood. The latter is one of the main reasons of the suggested strategy of laser heating of tumors in the therapeutic window of semitransparency when the tumor asphyxiation is considered as one of important weapons against the cancer. The other advantages of this advanced strategy of a soft thermal treatment (in few of sessions), which is painless for patients, are discussed as well. Some features of modeling various heat transfer modes are also considered. The best choice between the simplest differential models for the radiative transfer calculations is dependent of the particular problem statement. The known finite-difference or finite element algorithms can be preferable in solving transient heat transfer problems. As a rule, it depends on the shape of the computational region. It is expected that this paper will help the colleagues to overcome some typical weaknesses of computational modeling of infrared photothermal treatment of superficial tumors.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45331149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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