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The use of modern polymeric materials as dielectrics makes it possible to increase operational characteristics of the elements of various electric power and electronic devices. The necessary combination of interconnected values of permissible electric field strength and maximum operating temperature is crucial when choosing a particular polymer material. The relationship of these parameters is nonlinear due to the nonlinear dependence the electrical resistivity and the thermal conductivity coefficient on temperature of the polymer material. This relationship can be represented in a closed analytical form of integral relations in which the variable limit of the integrals is the desired function describing the temperature distribution in the dielectric layer. A quantitative analysis of these ratios for five different polymeric materials with known electrothermal characteristics has been carried out. The results of calculations of the temperature state of the dielectric layer and the distribution in the layer of the absolute value of the electric field intensity are given. The presented results can be used to justify the choice of a particular polymer material as a dielectric in the designed devices.

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This work is devoted to the application of a generalized computational experiment for a comparative assessment of numerical methods accuracy. A generalized computational experiment allows one to obtain a numerical solution for a class of problems determined by the ranges of defining parameters variation. The approaches to the application of a generalized computational experiment in the presence of a reference solution and in its absence are dis-cussed. An example of constructing error surfaces is given when the solvers of the OpenFOAM software package are compared. The classic inviscid problem of oblique shock wave is used as a basic task. Variations of the key parameters of the problem — the Mach number and angle of attack — are considered. An example of the problem of flow around a cone at an angle of attack with varying Mach number, cone angle and angle of attack is also considered. The concept of an error index is introduced as an integral characteristic of deviations from the exact solution for each solver in the class of problems under consideration.

This paper is devoted to comparative analysis of numerical methods accuracy. Comparative estimation of accuracy is performed for numerical methods presented as solvers integrated to open sotware package OpenFOAM. Three different OpenFOAM solvers are selected to numerically solve the problem of supersonic flow around a cone. The angle of attack, cone half-angle and Mach number were varied in the selected ranges with a certain step. This approach is implemented using a generalized computational experiment that allows, based on parallel technologies, the simultaneous solution of the same basic problem with different input parameters. A number of test calculations were carried out. The deviation fields of gas-dynamic quantities for all solvers are analyzed. The construction of a generalized computational experiment made it possible to compare the accuracy of the considered solvers not only for one, separately taken problem, but for a class of problems specified by the ranges of variation of the determining parameters. Such an assessment of accuracy can be very useful for users of the software package when choosing a solver. Also, the results obtained can be useful for solver developers.