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The paper presents the results of experimental study of disturbances generated by an electric discharge. Tthe disturbances occur in the zone of interaction of a shock wave and a boundary layer (the income shock wave has the Mach number М = 1.43). Experiments were carried out in a supersonic wind tunnel with the unit Reynolds number Re₁ = 11×10⁶ 1/m. The flow velocity was measured using the PIV method and hot wire method. The artificial disturbances are generated by a periodic pulsed electric charge; the charge facility is allocated at the model surface upstream the interaction zone. The discharge time is less than 100 ns: this enables creating a wide-spectrum disturbance inside the boundary layer. The method of phase-synchronous measurement with the ensemble averaging for realization produces the spatial and temporal characteristics of disturbances generated in the interaction zone. The major growth of initial disturbances occurs in the shear layer behind the shock wave/boundary layer interaction zone (here the flow is turbulent).

In the present paper, a computational study of the influence of solar and thermal radiation on the formation of wind and temperature conditions in urban environment is carried out using the example of a region of Krasnoyarsk in winter. For calculations, a developed microscale mathematical model of urban atmosphere was used. The calculation results showed that the presence of radiation in the daytime leads to an increase in temperature and average speed of wind, as well as to the formation of an unsteady wind regime in the urban environment.

Nonlinear waves in a rectilinear rivulet flowing down a vertical plate are investigated on the basis of the developed semi-analytical model. The characteristics of nonlinear quasi-two-dimensional steady-state traveling waves are obtained numerically. Another wave family (the family of double-humped waves), branching off from the first family by doubling the spatial period, is found for small values of the wave number. It is shown that steady-state traveling waves do not exist in a certain narrow range of the excitation frequency, but a pulsating wave mode is realized.

The paper considers experimental data on the dynamics of superfluid helium in a U-shaped cylindrical channel. An experimental cell and a methodology for investigations, parameter measuring and obtained data processing are described. When a heat flux is applied near the heater, vapor can appear, and the interfacial surface executes regular oscillations of macroscopic amplitude with a constant frequency. The dependences of the interfacial surface position and the corresponding parameters on time are given. The obtained experimental results are interpreted based on the earlier obtained analytical solution.

The effect of barodiffusion on the dynamics of gas bubble growth in a highly viscous, gas-saturated magmatic melt undergoing rapid decompression is studied. A mathematical model of the process, which represents a joint dynamic and diffusion problem, is proposed. It is shown that as the bubble grows, a diffusive boundary layer is formed around it, leading to the appearance of a large viscosity gradient in the melt and, as a consequence, to a large pressure gradient. A semi-analytical solution of the problem based on the existence of a quasi-stationary state for the bubble growth process is found. It is shown that the effect of barodiffusion is significant at the initial and transient stages of the process. Its influence decreases with time and disappears completely at the stage of diffusion.

Based on the hypothesis of quasi-stationarity, relations were obtained for calculating the unsteady process of filling a vacuum vessel. As a criterion for the completion of the filling process, the admissible degree of pressure increase in the vacuum vessel is adopted. An analysis was made of the possibilities of increasing the duration of the filling process for a vacuum vessel of a given volume.

The density of liquid mixtures of lithium and potassium fluorides with a content of 51.2 and 71.1 mol % LiF was measured using gamma-ray attenuation technique in the temperature range from liquidus to 1000-1190 K. For a mixture of near-eutectic composition (51.2 mol % LiF), the relative density change during the solid-liquid phase transition and the density in the solid state near the melting point were directly determined for the first time. The concentration dependences of the molar volume and volumetric coefficient of thermal expansion for the LiF-KF liquid system were plotted on the basis of the experimental and literature data. The obtained dependences were found to be close to the concentration dependences of the corresponding volumetric properties for ideal solutions.

The cooling rates of the studied alloy samples were determined in the "cooling" mode, by constructing thermograms of cooling alloys and their subsequent differentiation. Considering the heat capacity of the standard (Al brand A5N) and the cooling rates of the samples and the standard, the temperature dependence of the heat capacity of the aluminum alloy AlCu4,5Mg1 doped with calcium was calculated. Computer processing of the results served to obtain a polynomial of the temperature dependence of the heat capacity of alloys in the form of a four-term equation with the correlation coefficient R ≤ 0.999. It has been found that the heat capacity, enthalpy, and entropy of the alloys increase with increasing temperature, while the value of the Gibbs energy decreases. Additions of calcium in the range of 0.05 -1.0 wt. % reduce the heat capacity, heat transfer coefficient, enthalpy and entropy of the AlCu4,5Mg1 aluminum alloy, and the Gibbs energy has an inverse relationship.

In endoreversible cycles, irreversibility is considered only between the systems and their surroundings. In this paper, the modelling of heat interaction with a solar regenerative Brayton cycle is studied with regard to various fidelities based on the first and second laws of thermodynamics. The effect of linearity and nonlinearity related to the both convective and radiative heat interactions with the hot and cold reservoirs as well as radiation losses of the solar Brayton cycle have been studied, which is complementary to similar attempts for Carnot cycle. Total efficiencies are compared between various implemented models. The effect of temperature of six critical sections of the whole engine on the collector efficiency, cycle thermal efficiency and the system total efficiency has been studied. Besides, a comparison is done for a real example to show the importance of considering the nonlinearities for calculating thermal efficiency of a closed-loop Brayton cycle at different hot source temperatures, as well. These would help more efficient analysis of the emerging power cycles that can accelerate progress toward low-carbon power production.

The results of thermodynamic calculations and experimental studies on plasma processing of ash-and-slag waste and oil refinery waste with production of fuel gas and inert mineral material are presented. The calculated and experimental data on plasma-chemical processing of oil refinery waste are compared