CALCULATION OF THE TEMPERATURE AND THERMAL STRESS AT HEAT TRANSFER COEFFICIENT DEPENDING ON THE TEMPERATURE OF BODY SURFACE

The mathematical problem definition considering dependence of heat transfer coefficient on surface temperature in case of heating (chilling) of bodies of the correct geometrical form in the form of an unrestricted plate, cylinder or sphere, in case of free convection in unrestricted amount was for the first time written down, thereby making the task of heat conductivity nonlinear. The decision for model of thermally thin body was received. The calculation method for the surface temperatures at initial stage was developed. On the basis of the integrated linearizing transformations the engineering method of fields of temperatures and axial thermal tension in a quasistationary stage of heating (chilling) of bodies of the correct geometrical form was developed for the case of the heat exchange coefficient depending on surface temperature under the sedate law according to the mode of free convection: laminar, transitional or turbulent. Verification of decisions on model of fixed heat transfer coefficient have shown that the error of decisions is acceptable for engineering calculations, and not accounting of the dependence of heat transfer coefficient on temperature can result in big inaccuracies. Formulas for calculation of axial thermal tension are given for any point of the body: on a surface and in the center.

heating, cooling, bodies of an initial form, initial and quasistationary stages, heat transfer coefficient, surface temperature, temperature fields, thermal tension, engineering calculation

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