About the authors

First name, Middle name, Last name, Scientific degree, Scientific rank, Current position. Full and brief name of the organization, The organization address. | Renat A. Sadykov, doctor of Technical Sciences, professor, Kazan State University of Architecture and Engineering, Kazan, Russian Federation Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it Aida K. Mukhamezianova postgraduate student, Kazan State University of Architecture and Engineering, Kazan, Russian Federation Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it Svetlana A. Filimonova Engineer-designer of the 1st category, LLC "Metropolis", Moscow, Russian Federation E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it |

Title of the article | Analytical and numerical calculations of the quasi-steady-state heat transfer mode in the enclosing structures of buildings and structures |

Abstract. | In real operating conditions of buildings and constructions, all transfer processes proceed under unsteady modes, which is associated with continuous changes in the parameters of the state of the outside air (seasonal, daily and shorter in time fluctuations), heat release and accumulation of heat and moisture in rooms as a result of functional processes and work of engineering and ecological systems of building and construction functioning (air conditioning, ventilation, heating, etc.). Therefore, the study of unsteady and quasi-steady transfer modes of buildings and constructions in the enclosing structures has a direct practical application and it is an urgent problem of our time. The aim of the study is physical and mathematical description of the quasi-steady process of conductive heat transfer through the enclosing structures of buildings with a periodic change in the outside air temperature and generalization of the obtained analytical and numerical solutions of the boundary value problem and the performed heat engineering calculations for any other enclosing structures and climatic zones. The objectives of the study are the analytical solution of unsteady and quasi-steady boundary value problems and the writing of the corresponding algorithms for calculating the temperature fields in the enclosing structures in the Mathcad and Microsoft Excel software, as well as the numerical modeling of the unsteady and quasi-steady conductive transfer in the Elcut and Ansys Fluent software. The main results of the research are that the authors formalized mathematical models of the boundary value problem of unsteady and quasi-steady heat transfer, which were used to create computational programs in Mathcad and Microsoft Excel software. The correctness of the statement of the boundary value problem and the calculation algorithms was determined by comparing analytical solutions with the results of calculations in the Elcut and Ansys Fluent software. It was also found that the calculation of a multilayer enclosing structure at extreme values of outside air temperatures in steady modes is necessary, but to obtain an objective assessment of the energy efficiency of building constructions, calculations are also required under unsteady modes of operation of buildings and constructions, which more accurately reflect the real processes of heat and mass transfer in them, taking into account the amplitude of fluctuations in outside temperatures. The paper investigates the change in the temperature of the enclosing structures of buildings and constructions during the day and formalizes a mathematical model for the transfer process of heat transfer through a single-layer enclosing structure. Also, a study of quasi-steady heat transfer through the enclosing structure was carried out using analytical and numerical methods, and heat engineering calculations applicable for any enclosing structures and climatic zones were presented. The significance of the results obtained for the construction industry lies in the fact that in the conditions of the intensive development of the construction industry and an increase in its efficiency associated with the development of new technologies, a decrease in material and energy costs for the production of building materials, the issue of taking into account the unsteadiness of heat and mass transfer processes in heat engineering calculations of various enclosing structures becomes urgent. |

Keywords. | : mathematical model, enclosing structure, boundary value problem, heat transfer, calculation, mode, heat wave. |

For citations: | Sadykov R.A., Mukhamezianova A.K, Filimonova S.A. Analytical and numerical calculations of the quasi-steady-state heat transfer mode in the enclosing structures of buildings and structures//News KSUAE 2022 №1(59). С 90-102. DOI: 10.52409/20731523_2022_1_90 |