Calculation of a thermal contact resistance of power plants’ elements with wavy surfaces
Aircraft engines and power generators
Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
A numerical method for determining the thermal contact resistance of wavy surfaces is considered. This method is based on the solution of the mechanical problem with the latest achievements of the contact mechanics and the elemental analysis of the heat flow’s passage through analyzed connections which are modeled by superimposing the roughness on the wavy surface.
Described stages of the simulation allow to determine the actual area of the contacting surfaces using software package ANSYS. Deformation is calculated by the known properties of the contacting materials and attached specific load. Later a temperature field is defined by the known geometric model and given values of the heat flow, the thermal conductivity and a temperature of one of the surfaces. Further the temperature field is compared with the temperature distribution of uniform material which characterizes the ideal connection. The value of the thermal contact resistance is defined as the temperature difference between the second boundary of the analyzed real and ideal connections which is divided by the heat flow density. The results of calculations are compared and demonstrate a good coincidence with the known experimental data and the known complex analytical functions. The results of the work are illustrated with drawings of the three-dimensional stress distribution and temperature field near the contact spots. Comparison of the results which are obtained in this work are made in the form of two graphs, which shows the data of experiments and calculations on the analytic dependence. The results open up the possibility to abandon complex formulas which are based on empirical equations.
The results of the research work allow the proposed method to be used widely for finding the temperature difference in the thermal loaded connections of the real constructions.
Keywords:wavy surface, thermal contacting, thermal resistance, model elements
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