In this paper we carried out experimental study of a heat flux on the shocktube surface during passage of shock wave using a gradient sensor based on bismuth single crystal. The obtained experimental data were compared with numerical simulation results. It is shown that after passing through contact surface that separating the hot "plug" and pushing gas, the colder gas flow is mixed with the hot one. The heat transfer on the contact surface was evaluated. Keywords: shock tube, heat flux, non-stationary heat measurements.

Experimental study has been made of the ignition of a subcritical microwave discharge at pressures in the range 55–79 Torr with the initiation by pulsed laser radiation (58 mJ in a pulse). A rise of 36

This article devoted to the study of gas heating in the region of an electric interelectrode discharge. The dynamics of local heating is studied using numerical methods and experimentally using an interferometer. The research results make it possible to evaluate the change in the temperature distribution in the cross section of the discharge track, the dynamics of the maximum heating temperature and the size of the heated area.

In this paper we carried out experimental study of a heat flux on the shocktube surface during passage of shock wave using a gradient sensor based on bismuth single crystal. The obtained experimental data were compared with numerical simulation results. It is shown that after passing through contact surface that separating the hot "plug" and pushing gas, the colder gas flow is mixed with the hot one. The heat transfer on the contact surface was evaluated.

This article devoted to the study of gas heating in the region of an electric interelectrode discharge. The dynamics of local heating is studied using numerical methods and experimentally using an interferometer. The research results make it possible to evaluate the change in the temperature distribution in the cross section of the discharge track, the dynamics of the maximum heating temperature and the size of the heated area. Keywords: pulsed interelectrode discharge, low-temperature plasma, gas heating.

An experimental and numerical study of interaction between an oblique shock wave and density inhomogeneity is done. The inhomogeneity is created by interelectrode spark discharge in the oncoming flow with a Mach number of 2. As a result of the experiment, we obtained gradient heat flux sensor data and took shadow photography of the process.

In this work we performed calibration of the gradient heat flux sensor made of bismuth single crystal. The value of the volt-watt sensitivity of the sensor is found and a data processing method based on the one-dimensional heat equation for a thin plate is presented. An experimental study of the heat flux on the frontal surface of the cylinder after a laser discharge was carried out. The data obtained as a result of the experiment were processed by the proposed method.

The gradient heat flux sensor made of a bismuth single crystal is calibrated. The volt–watt sensitivity of the sensor is determined and the method of data processing based on the 1D heat conduction equation for a thin plate is proposed. This method is tested on experimental data obtained for the initiation of a laser discharge in a calm atmosphere and in a supersonic gas flow.

The first 200 ns of an air pulsed interelectrode discharge are considered with gas dynamics taken into account. It is this initial stage that is of most importance for determination of the properties of the heating power released in the interelectrode gap. Data are presented on heating of the near-cathode and -anode layers and the gap by the moment when the transient stage in the development of the discharge ends. A spherical expanding shock wave is produced near the cathode.

The possibility of developing a apparatus based on the results of kinetic calculations of the processes, occurring in it, is considered. The studies were carried out with the system solid-liquid-vapor-gas medium with a continuous increase in vacuum above the surface of a layer of the dispersed material. The presence of the liquid phase and the vapor-gas phase in equilibrium with it makes it possible to provide a change in concentration, structure, or cooling in the system due to artificial disturbance of the dynamic equilibrium of the system. To develop a mathematical model of the liquid removal process, a model of ideal mixing in the vapor-gas phase and a layer of the dispersed material was adopted. The calculation results are presented in the form of kinetic dependences of the main process parameters. Calculation of the apparatus is carried out at the highest load in the vapor-gas phase during the period of removal of the free moisture. In this case, the influence of rarefaction on the physical characteristics of the removed fluids and the design features of the apparatus being calculated was taken into account.

The formation dynamics of the parameters of a microwave discharge in air localized at electric field maxima created by a specially developed focusing system is investigated using numerical simulations within an extended hydrodynamic model. All main parameters of the microwave discharge plasma are determined. The results on neutral gas heating demonstrate good agreement with the earlier experimental results.

Analysis of the literature revealed a lack of filtering centrifuges, which include the difficulty of regenerating the filtering surface. The presented constructive solutions for its elimination provide only local, but not complete regeneration of the filtering surface. The authors investigated the regeneration of filter elements when the blades rotate around the axis as a result of the engagement of parts of the rotary device. In order to exclude shock loads in the process of turning, various cam designs are considered, the best of which is a fork cam.

A special setup was designed and built at St. Petersburg State University for providing experimental research in flow dynamics of the of air-water mixtures in a pipeline. The test section of the setup allows simulating a wide range of flow regimes of a gas-liquid mixture. The parameters of the experimental setup are given; the initial test results are discussed.

The action of differently oriented magnetic fields on the parameters of bow shock created in the vicinity of aerodynamic bodies placed into the supersonic gas-plasma flows is studied. For these experiments two types of the high speed plasma jet sources are used—magneto-plasma compressor (MPC) and powerful pulse capillary type discharge. MPC allows to create the plasma jets with gas flow velocity of 10 ± 2 km/s, lifetime 30–50 μs, temperature Te ≈ 3 ± 0.5 eV, electron density about ne ∼ 1016cm−3 and temperature Te ≈ 3 ± 0.5 eV. The jet source based on powerful capillary discharge creates the flows with lifetime 1–20 ms, Mach numbers 3–8, plasma flow velocity 3–10 km/s, vibration and rotation temperatures 9000–14000 and 3800–6000 K respectively. The results of our first experiments show the possibility of using gas-plasma sources based on MPC and powerful capillary discharge for aerodynamic and radiophysical experiments. Comparatively small magnetic field B = 0.23–0.5 T, applied to the obtained bow shocks, essentially modify them. This can lead to a change in shape and an increase in the distance between the detached shock wave and the streamlined body surface if B is parallel to the jet velocity or to decrease this parameter if B is orthogonal to the oncoming flow. Probably, the first case can be useful for reducing the thermal load and aerodynamic drug of streamlined body and the second case can be used to control the radio-transparency of the plasma layer and solving the blackout problem.

Existence and intensive growth of heat flux on a vehicle is one of the main problems in hypersonic flight. Experimental study of heat flux in the stagnation point of a blunt cylinder in supersonic flow was made using gradient heat flux sensor. It was found that a transfer function of the measuring system should be used for obtaining data at fast-changing heat flux measurements. It was established that it was possible to produce a short-term heat transfer from the surface of streamlined body with the help of microwave discharge. Numerical simulation showed that it is possible to change nature of the flow by means of local energy deposition in case of streamlined wedge.

The influence of density inhomogeneity on aerodynamic characteristics of a blunt cylinder has been studied experimentally. The inhomogeneity of the supersonic free stream was obtained by injection of a thin helium jet into the main air stream. The interaction of the density inhomogeneity of the supersonic flow and shock wave resulted in a decrease of drag and heat flux on the blunt cylinder.

The development of the mathematical model that describes a reduction zone of the gasifier installation is described in this paper.

The article is devoted to experimental and numerical studies of the efficiency of microwave energy deposition into a supersonic flow around the blunt cylinder at different Mach numbers. Identical conditions for energy deposition have been kept in the experiments, thus allowing to evaluate the pure effect of varying Mach number on the pressure drop. Euler equations are solved numerically to model the corresponding unsteady flow compressed gas. The results of numerical simulations are compared to the data obtained from the physical experiments. It is shown that the momentum, which the body receives during interaction of the gas domain modified by microwave discharge with a shock layer before the body, increases almost linearly with rising of Mach number and the efficiency of energy deposition also rises.