On the Method of Construction of the Dependence of the Heat Extension Coefficient on Temperature in Heat-resistant Alloys
Abstract
In this paper, we consider methods and methods for studying rods from high-temperature alloys, in particular, the study of the dependence of the coefficient of thermal expansion on temperature. According to the tasks of the paper, methods are developed for taking into account the presence of local surface heat exchanges, temperatures, and internal point heat sources in the study of rods made of high-temperature alloys. The scientific significance of the project is due to the fact that the results of the development can be used for in-depth study of the nonlinear thermal and physical state of the structural rod elements that work in the presence of heterogeneous types of heat sources. Such designs include gas-generating, nuclear, thermal and hydrogen power plants, as well as jet engines and internal combustion engines. In order to ensure continuous reliable operation of these facilities, the authors developed fundamental methods that allow to adequately simulate nonlinear thermophysical processes in the rod bearing elements of installations taking into account simultaneous presence of local thermal insulation, heat exchange, temperatures, and internal point heat sources. The laws of the distribution of temperature, elastic, temperature and thermoelastic components of strains and stresses, as well as displacement, are obtained. This became the basis for the creation in the future of a program in the programming language PYTHON, with the help of which it is possible to construct the corresponding fields of temperature distribution, all the components of deformation, stress and displacement in the form of graphs.
Keywords
Download Options
Introduction
Bearing elements of many designs of power objects, such as nuclear, thermal and gas-generating power plants, as well as modern metallurgical plants, mainly work under the influence of complex heterogeneous heat sources. Some load-bearing elements of jet and hydrogen engines, as well as internal combustion engines, work similarly under the influence of local temperatures.
In most cases, the supporting elements have a structural form of a rod of limited length, and are made of heat-resistant materials. This is due to the fact that the strength characteristics of heat-resistant materials are usually higher than those of conventional materials. Simultaneous long-term exposure to rod-bearing elements of dissimilar heat sources leads to the emergence of a stable complex thermophysical state in the system. For example, in the case where the rod-bearing structural member of the structure is clamped at one end and the other end is free, it is prolonged due to the long-term action of dissimilar heat sources. In this case, the amount of elongation depends on the types and quantities of the operating heat sources, the presence of local thermal insulation and heat exchange, as well as the heat transfer coefficient, ambient temperature, rod length, thermal conductivity and thermal expansion of the heat-resistant alloy.
n the case when the rod is pinched at both ends, a steady state will occur only after the temperature distribution, a steadystate displacement distribution field and a compressive force arise, and a steady-state distribution field of the thermoelastic and temperature components of the stress and deformation appears.
Conclusion
The developed technique for taking into account the simultaneous presence in the rod of the heat-resistant alloy of local surface heat exchanges allowed:
1) To obtain a resolving system of linear algebraic equations taking into account natural boundary conditions for a limited length of a rod made of a heat resistant alloy under the influence of local surface heat exchange;
2) To obtain, within the framework of the task at hand, the laws for the distribution of temperature, elastic, temperature, and thermoelastic components of deformations and stresses, and also for displacement;
3) Within the framework of the task set, to create a program in PYTHON programming language, with the help of which the corresponding fields of temperature distribution, all the components of deformation, stress and displacement in the form of graphs are constructed.