On the problem of modeling temperature fields in bodies with variable boundaries

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Introduction. When melting, solidifying and oxidizing a metal, the problem arises of calculating the temperature field in areas with time-varying boundaries. Usually, to solve the heat equation in such cases, the method of catching the boundary into a node of a spatial grid is used, which necessitates the use of a variable time step in calculations, in addition, the number of spatial nodes will also be variable. All this leads to a change in the amount of computational work. However, in many cases the method of grids with moving nodes may be more preferable, in this case there is no need to change the number of spatial nodes and the time step. Purpose of the study. Develop an algorithm for approximating the convective boundary condition for grids with moving nodes. Materials and methods. The analysis and generalization of literature data on the problem is carried out. It has been established that the direct replacement of derivatives in the boundary condition by finite differences leads to a large error in calculating the surface temperature and, as a result, the entire temperature field of the body. When using a grid with a constant spatial step for a finite-difference approximation of the boundary condition, one can use the Beck formula. There is no formula similar to the Beck formula in the literature for meshes with moving nodes, so the problem arises of determining such a formula. To solve the stated problem of approximation, the method of heat balance for an elementary cell near the surface of the body is applied. Results. An analogue of the Beck formula for grids with moving nodes is found. The obtained finite-difference formula was tested, including with the help of a computational experiment. Conclusion. The obtained formula for approximating the convective boundary condition for grids with moving nodes can be a kind of addition to the theoretical foundations of the method of grids with moving nodes used in practice for calculating temperature fields in areas with variable boundaries; its application makes it possible to increase the accuracy of calculating the temperature field of a body.

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Finite-difference scheme, convective boundary condition, the grid method with mobilenodes, computational domain with moving boundaries, temperature field approximation

Короткий адрес: https://sciup.org/147240361

IDR: 147240361   |   DOI: 10.14529/met230106

Список литературы On the problem of modeling temperature fields in bodies with variable boundaries

  • Tsaplin A.I., Nikulin I.L. Modelirovanie teplofizicheskikh protsessov i ob"ektov v metallurgii: ucheb. posobie [Modeling of Thermal Processes and Objects in Metallurgy: a Tutorial]. Perm: Perm State Technical University Publ.; 2011. 299 p. (In Russ.)
  • Panferov V.I. [On the Optimal Control of the Processes of Heating (Cooling) and the Solidification of the Metal]. Izvestiya vuzov. Chernaya metallurgiya = Izvestiya. Ferrous metallurgy. 1982;4:129–132. (In Russ.)
  • Panferov V.I. [The Optimal Control of Heating Oxidation of Massive Bodies in Heat Exchange with the Environment Through the Surface Layer of Scale]. Izvestiya vuzov. Chernaya metallurgiya = Izvestiya. Ferrous metallurgy. 1982;2:87–90. (In Russ.)
  • Panferov V.I. [Identification of Thermal Conditions of Piping Systems]. Bulletin of the South Ural State University. Ser. Construction Engineering and Architecture. 2005;3(13):85–90. (In Russ.)
  • Sosnovskiy A.V. [Mathematical Modeling of the Influence of the Thickness of the Snow Cover on Permafrost Degradation Under Climate Warming]. Earth Cryosphere. 2006;X(3):83–88. (In Russ.)
  • Gorelik Ya.B., Romanyuk S.N., Seleznev A.A. [Mathematical Modeling of the Influence of the Thickness of the Snow Cover on Permafrost Degradation Under Climate Warming]. Earth Cryosphere. 2014;XVIII(1):57–64. (In Russ.)
  • Kuznetsov G.V., Sheremet M.A. Raznostnye metody resheniya zadach teploprovodnosti: ucheb. posobie [Difference Methods for Solving Heat Conduction: a Tutorial]. Tomsk: TPU Publ.; 2007. 172 p. (In Russ.)
  • Arutyunov V.A., Bukhmirov V.V., Krupennikov S.A. Matematicheskoe modelirovanie teplovoy raboty promyshlennykh pechey [Mathematical Modeling of the Thermal Performance of Industrial Furnaces]. Moscow: Metallurgiya; 1990. 239 p. (In Russ.)
  • Solov'ev A.E., Yashchenko N.M. [Solution of the Problem of the Motion of the Interface Between Two Media Conditions]. Journal of engineering physics and thermophysics. 1981;X(2):370–371. (In Russ.)
  • Panferov V.I., Parsunkin B.N. [Modeling of Heating Oxidation of Massive Bodies with the Method of Nets “mobile” Sites]. Izvestiya vuzov. Chernaya metallurgiya = Izvestiya. Ferrous metallurgy, 1982;4:105–109. (In Russ.)
  • Panferov V.I., Mikhan'kova Yu.O. [Solution of the Stefan Problem for a Disconnected Heating Pipeline]. In: Teplofizika i informatika v metallurgii: dostizheniya i problemy: materialy mezhdunar. konf. Ekaterinburg, UGTU-UPI [Thermal Physics and Computer Science in Metallurgy: Achievements and Challenges: Proceedings of the International Conference. Ekaterinburg, Ural State Technical University]. Ekaterinburg: Ural State Technical University; 2000. P. 284–288. (In Russ.)
  • Panferov S.V., Panferov V.I. Numerical Approximation of Convective Boundary Conditions for Grids with Mobile Nodes. Bulletin of the South Ural State University. Ser. Power Engineering. 2015;15(4):13–18. (In Russ.) DOI: 10.14529/power150402
  • Zherebyat'ev I.F., Luk'yanov A.T. Matematicheskoe modelirovanie uravneniy tipa teploprovodnosti s razryvnymi koeffitsientami [Mathematical Modeling of the Thermal Conductivity Type Equations with Discontinuous Coefficients]. Moscow: Energiya: 1968. 56 p. (In Russ.)
  • Beck J. [Numerical Approximation of the Convective Boundary Condition]. Trudy amerikanskogo obshchestva inzhenerov-mekhanikov. Teploperedacha (russkiy perevod) [Proceedings of the American Society of Mechanical Engineers. Heat Transfer (Russian Translation)]. 1962;1:109–110. (In Russ.)
  • Dul'nev G.N., Parfenov V.G., Sigalov A.V. Primenenie EVM dlya resheniya zadach teploobmena [The Use of Computers for Solving Problems of Heat Transfer]. Moscow: Vysshaya shkola; 1990. 207 p. (In Russ.)
  • Beck J., Blackwell B., St. Clair C., Jr. Nekorrektnye obratnye zadachi teploprovodnosti [Incorrect Inverse Heat Conduction Problems]. Transl. from Engl. Moscow: Mir; 1989. 312 p. (In Russ.)
  • Ryaben'kiy, V.S. Vvedenie v vychislitel'nuyu matematiku: ucheb. posobie [Introduction to Computational Mathematics: a Tutorial]. Moscow: Fizmatlit; 2000. 296 p. (In Russ.)
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