Analysis of Geometric Characteristics of Two-Phase Polymer-Solvent Systems During the Separation of Solutions According to the Intensity of the Image of Micrographs

This paper describes a geometric model for assessing the effective area of solar panels with regard to their shadowing when the object is illuminated by the solar flow from a given direction. Using energy methods, the flow density, the irradiation created by it, and the exposure in radiant or effective units of measurement were determined. Both physical and mathematical formulation of the problem of assessing the energy efficiency of solar panels using the method of geometric modeling are described. To evaluate energy efficiency, a voxel geometric model was selected that discretizes the computational space. A significant difference in the developed voxel geometric model is that it is multivalued, i.e. uses not a 2-digit, but a 4-digit code. Such ambiguity allows the decisive algorithm to quickly “figure out” the origin of the shadow source when calculating the total effective area of solar panels. The described software implementation of the geometric model, graphical shell, and model verification results can be used in the optimization system for designing spacecraft and other solar energy facilities.

Geometric method for assessing the shadowing of objects in solar power engineering

Markin

2020

Mathematical modeling of coupled heat transfer on cooled gas turbine blades

Sun¹,

Колесник

Kuznetsova

2020

The paper presents a physico-mathematical model for determining the heat transfer parameters between viscous gasdynamic flotations and cooled gas turbine blades made using the technology of composite permeable membranes (CPM). The mathematical model includes equations of dynamic and thermal boundary layers taking into account injection, three-dimensional transient heat conduction in CPM cooled frames, complex hydraulic flow and cooling inside the channels of a cooled blade with air taken from the power plant compressor. A complex problem was solved to determine the thermal state of microrocket engines, where a method was proposed for immersing a multiply-connected domain in a region of the simplest form. A new economical, absolutely stable method is proposed for numerically solving of spatial nonstationary heat transfer problems in multiply-connected domains. The results obtained showed greater cooling efficiency at lower cooling medium costs.

Method for solving plane unsteady contact problems for rigid stamp and elastic half-space with a cavity of arbitrary geometry and location

Arutiunian

Кузнецова

et al. 2020

In the work, the process of unsteady contact interaction of rigid stamp and elastic half-space having a recessed cavity of arbitrary geometry and location with a smooth boundary was investigated. Three variants of contact conditions are considered: free slip, rigid coupling, and bonded contact. The method for solving the problem is constructed using boundary integral equations. To obtain boundary integral equations, the dynamic reciprocal work theorem is used. The kernels of integral operators are bulk Green functions for the elastic plane. Because of straight-line approximations of the domain boundaries with respect to the spatial variable and straight-line approximations of the boundary values of the desired functions with respect to time, the problem is reduced to solving a system of algebraic equations with respect to the pivotal values of the desired displacements and stresses at each time interval. One of the axes is directed along the regular boundary of half-space, the second - deep into half-space.