The set of operations on diagnosing the changes in the properties of materials due to aging includes accelerated climate tests (ACTs) and pre- and post-ACT performance tests. Along with the use of various methods for diagnosing defects that arise and develop during aging, it is also important to determine changes in the thermophysical, hydrophysical, and other properties of materials subject to long-term operation that are associated with changes in the material structure. In this paper, we present a method for synchronous calculation of changes in thermophysical and hydrophysical properties of materials due to material aging and respective changes to the hygrothermal modes of products under long-term storage and operation. An experimental setup and a method for experimental-analytical determination of the thermophysical properties of materials at variable heating rates, as well as a method of synchronous calculation, are presented. The experimental-analytical determination method was developed using the results of thermal testing of specimens both subjected to ACT and without ACT. The analysis of the test results makes use of the approximation-superposition method to solve the inverse heat conduction problem.

The paper provides a designed under the supervision and with the participation of authors of the paper complex of methods of accounting for structural inhomogeneities of elements of a Thermal Protection System (TPS) made of C-C composites used to estimate ablated shapes of high-speed Flight Vehicles (FVs) and corresponding methods of measuring and processing of the needed structural parameters of C-C composites. During the mass ablation along a flight trajectory reinforcing elements and a graphitized matrix ablate differently, and there appears primary large-scale roughness on the surface. Moreover, pores, shells, and other fine-grained inhomogeneities outcrop forming the secondary finely divided roughness. Roughness impacts heat exchange, and summary equivalent roughness parameters are used to estimate FVs ablated shapes. A C-C composite graphitation degree that is defined with the X-ray diffraction study also influences an ablation rate. The density of materials is linearly related to their porosity, and for a number of currently in use and promising materials the density distributions were studied using computer tomography as well as the distribution of pores, shells, and other fine-grained inhomogeneities over volume of TPS elements was examined with electron microscopes. X-ray diffraction studies of the C-C composites were also carried out. Comparative computations of ablated shapes and aerodynamic characteristics of a model cylindrical FV with applied TPS elements of the examined C-C composites were performed with the use of obtained results of tomography, electron microscopic and X-ray diffraction studies.

An ionized flow around the RAM C-II space vehicle is studied by the direct simulation Monte Carlo method in the range of altitudes of 73 to 81 km. It is shown that the predicted value of the plasma density in the shock layer essentially depends on the approach to simulation of high-temperature nonequilibrium dissociation. Good agreement of the results of numerical simulation with flight experiment data is obtained.

Preliminary results of numerical simulation of the passage of an electromagnetic wave through the ionized shock layer around a blunt-nosed body in a hypersonic flow are presented. For calculation of the electromagnetic field, a field of flow is used that is computed using the software package PlasmAero developed at the Joint Institute for High Temperatures, Russian Academy of Sciences. Solutions are presented for a few wavelengths and several angles of wave incidence. The electron concentration for the flow under study is shown to be too high near the nose of the streamlined body, which leads to a significant weakening of the electromagnetic field on the surface of the body. At the same time, the situation downstream does not look as hopeless from the point of view of signal attenuation.

Представлен предметно-ориентированный программно-методический комплекс, позволяющий эффективно выполнять комплексное моделирование гидродинамики и динамики подводных аппаратов, последовательно решать частные задачи с учётом конструктивных особенностей аппарата, условий обтекания, способов обеспечения выхода аппарата из пускового устройства и устойчивого движения его по траектории.