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It is shown that the “new methodologies” of processing and using results calculated for rotating detonation engines, as well as those of recent measurement of forces acting on the models of ramjet (rotorless) models in “hot” and “cold” runs in supersonic test benches, which are developed and promoted by S.M. Frolov and V.I Zvegintsev with their colleagues, are incorrect.

The traditional approach to measuring the thrust of air-breathing jet engines (ABJEs) was proposed by B.S. Stechkin in 1929. In this approach, the thrust is determined as the difference between the momenta of the gas flows at the engine inlet and outlet. The approach involves some methodological and terminological problems. Based on a critical analysis of available concepts, the present article proposes a new approach to determining the ABJE thrust in the form of the decrease of the initial drag of the aircraft + ABJE system when the power plant operates with fuel supply and energy release. For the thrust thus obtained, we propose using the term “real thrust”. It is shown that the proposed approach eliminates terminological problems and simplifies the technique for measuring the thrust characteristics of the ABJE. The paper considers various options for applying the proposed approach to the determination of the “real thrust” for different cases of using and modeling ABJEs, including the calculation of flight trajectories of the aircraft with ABJE.

We present the experimental results on the thermal efficiency in a wall gas screen injected through inclined cylindrical holes along a smooth surface, and when a secondary flow is blown through cylindrical holes into a transverse trench. The thermal efficiency fields of the wall screen were measured using an infrared camera. In the case of blowing into a trench, the experimental data are characterized by an insignificant influence of the injection parameter on the thermal efficiency of the wall screen for all the trenches under study. It has been established that an increase in the trench depth leads to an increase in the thermal efficiency of the wall gas screen. The maximum increase in thermal efficiency is achieved for a trench with relative depth h/d = 0.94 . The data of the measurements presented are compared with the experimental and numerical results of other authors for the cases of injecting through the holes into a transverse trench.

Results of experimental and numerical studies of the properties of a turbulent boundary layer modified with a control action in the form of distributed air blowing through a high-technology perforated wall are presented. The wall is part of the surface of an elongated axisymmetric body in a low-velocity gas flow. The Reynolds number Re^** based on the momentum thickness δ^** ahead of the perforated region formed by holes 0.14 mm in diameter with microchannels with a small aspect ratio is 2660. The area-averaged blowing coefficient C_b varies in the interval 0 - 0.00885. As the streamwise coordinate increases up to the distance 550δ^** from the blowing region, the local friction is seen to decrease consistently; the greatest value of the local friction is 64% directly in the blowing region in the case of the maximum blowing intensity.

The thermal conductivity of the R-32/R-125 (15/85) mixture was investigated in the temperature range of 305 - 411 K and pressures of 0.1 - 1.8 MPa. Measurements were carried out by the stationary method of coaxial cylinders. The error of the experimental data on thermal conductivity was 1.5 - 2.5%, and the measurement errors of temperature and pressure did not exceed 0.05 K and 4 kPa, respectively. A generalizing equation for calculating the thermal conductivity as a function of pressure and temperature was obtained. The thermal conductivity on the condensation line and in the ideal gas state was determined.

Microchannel cooling systems are widespread due to their efficiency. In this work boiling of dielectric liquid FC-72 in a flat microchannel with a height of 66 μm and a width of 10 mm was studied. Heating was carried out by a thin-film ITO heater in direct contact with the working liquid. The flow regimes at boiling in a wide range of liquid flow rates were investigated. It is shown that boiling regimes in a flat microchannel differ significantly from the flow regimes in circular and rectangular mini- and microchannels. The dependences of heat flux on the temperature head have been plotted. The dependence of the heat transfer coefficient on the heat flux was investigated for different regimes of the two-phase flow.

This paper presents calculation results on plasma ignition and combustion of coal in the furnace of the PK-39-II boiler at Reftinskaya SDPP. For mathematical modeling of coal combustion in the boiler furnace, a three-dimensional mathematical model Cinar ICE and a software package for physical modeling and calculation of hydro-dynamics, heat and mass transfer and combustion of fuels in the volume of furnace devices were applied used. Cal-culations were performed for two regimes of pulverized coal combustion: the traditional one and using plasma activa-tion of coal combustion. It is shown that the use of plasma-fuel systems (PFS) allows optimization of the coal com-bustion process in the combustion chamber. Three-dimensional modeling of a pulverized coal furnace equipped with a PFS allows one to determine the optimal PFS layout on boilers of thermal power plants.

An experimental study of the specific heat capacity of gadolinium-scandium-gallium and calcium-niobium-gallium garnets widely used in laser technology and microelectronics was carried out by the method of differential scanning calorimetry. New experimental results on the specific isobaric heat capacity in the temperature range of 300 -1270 K were obtained; approximation equations and a table of recommended values for scientific and practical use were developed on their basis. The comparison with the known literature data was carried out. The estimated error of the data obtained was 2-4%.

Combustion of liquid hydrocarbons sprayed with a jet of superheated steam is experimentally studied using n-heptane as an example as a promising method for efficient and environmentally safe combustion. with forced air supply to the gas generation chamber. It is a modernized design of an atmospheric burner with a natural air inflow, studied by the authors earlier, and it allows obtaining additional information about the effect of changing the excess air ratio inside the device on the process of burning liquid fuel in the presence of superheated steam. New data on the environmental and energy characteristics of the burner under study were obtained based on thermocouple measurements, gas analysis of intermediate flame components, measurements of combustion efficiency and harmful emissions in the final combustion products. They were compared with characteristics of the burner with natural air inflow. It was found that formation of carbon monoxide during the combustion of heptane is reduced by 25%, and formation of nitrogen is reduced oxides by 15% with a decrease in the excess air ratio in the combustion chamber from 0.7 to 0.16. At the same time, a burner with a natural air inflow is characterized by a higher flame temperature and a shorter flame length. At that, the level of CO and NO_x emissions in all regimes corresponds to the European standard EN 267. It was determined that the forced air flow does not have a noticeable effect on the heat generated for the studied regimes, and the calorific value of fuel combustion in all cases is close to the higher calorific value of heptane, which indicates the high efficiency of the combustion method under study.

The experimental results on the turbulent flow structure in a lattice matrix cell, which is a region between intersecting ribs on the opposite walls of a flat channel, are presented. The angle between the ribs was 2β = 60º, 90º and 120º; the Reynolds number calculated from the average velocity and hydraulic diameter of the channel was varied in the range Re = (1 - 7)×10⁴. The aerodynamic characteristics of the flow inside a lattice matrix cell placed in a rectangular channel with a cross-section of 20 × 150 mm and a length of 400 mm were measured using a two-component laser Doppler anemometer (LDA). The flow structure was studied in individual cells of 15 × 15 mm, formed by crossing ribs on the opposite channel walls. The complex three-dimensional structure of the flow in the matrix cells and strong turbulence of the flow in the near-wall regions are shown. The installation of ribs leads to a significant increase in hydraulic losses, especially at large crossing angles.