Home – Home – Jornals – Advanced Search

The process of gas hydrocarbon combustion was tested in real (industrial) conditions on boilers with many burners. For key operation modes, the main regularities of emission from single flames were studied. The system of remote diagnostics was developed; it is suitable for selective monitoring of a single burner in the multi-burner configuration and supplies useful information for the operator about relative intensity of flames, oxygen, and hydrogen concentrations in flue gases. This information is valuable for optimization of gaseous fuel combustion. The equipment set was used in development of an automatic control system for processes at a heat station.

The paper presents the method and results for technical and economical study of a cogeneration plant with exhauster gas turbines fueled by solid fuel. The search of fundamental regularities of the processes allowed us to recommend optimal parameters for different variants of power plant operation and formulate recommendations for optimal configuration of a cogeneration plant with exhauster gas turbines.

Results of an experimental study of aerodynamic characteristics of models of two hypersonic re-entry vehicles (ARES-H aerospace demonstrator proposed by EADS-ST and EXPERT re-entry capsule proposed by ESA ESTEC) are presented. The experiments were performed in a new wind tunnel AT-303 at ITAM SB RAS in the range of free-stream Mach numbers

Characteristics of the fields of mean density and density fluctuations measured with introduction of periodic disturbances into a hypersonic viscous boundary layer on a flat plate are presented. The experiments are performed for a flow Mach number M_∞ = 21, Reynolds number per meter Re_1∞ = 6·10⁵ m^-1, and temperature factor of the surface T_w /T₀ = 0.26. The disturbances are introduced into the shock layer by an oblique gas-dynamic whistle.

Results of an experimental hydrodynamic and heat-transfer study of the turbulent separated flow developing over a system of several cross-flow ribs are reported. Conditions with low and high free-stream turbulence are considered. Visualization and heat-transfer data are presented, and a comparison for two turbulence levels is given. In the system of three or more ribs, a very unstable flow in the second inter-rib cell was observed under low-turbulence conditions. Under a high level of free-stream turbulence, the flow in the first inter-rib cell is unstable; this observation is supported by measured pressure distributions. Addition of each next rib makes the separation flow region behind the last rib and the pressure recovery region less extended, and decreases the coordinate at which the rate of heat transfer attains its maximum. In the high-turbulent flow, the heat-transfer intensification in the second inter-rib cell amounts to 30 %.

The effect of periodic blowing/suction on characteristics of a turbulent boundary layer formed on an axisymmetric body of revolution in a nominally gradientless incompressible flow is studied experimentally. The Reynolds number based on the momentum thickness at the location of an annular slot for blowing/suction is 1176. The dimensionless slot width in the wall units is 68. It is demonstrated that blowing/suction aimed at controlling the boundary-layer flow is a fairly effective method for controlling the near-wall turbulence structure and ensures a certain gain in friction drag over the initial configuration (the maximum gain reaches 25 30 %).

An ejector scheme intended for forming supersonic heterogeneous flows is experimentally examined as applied to conditions typical of cold gas-dynamic spraying. Pressure and temperature distributions in the supersonic part of the nozzle are reported, and critical operating regimes of the nozzle are identified. Specific features and advantages demonstrated by this scheme in practical applications are considered. Results of preliminary tests on the application of coatings with the use of the nozzle unit under study are presented.

A computational model for processes in the duct of an experimental setup consisting of a shock tube and an MHD duct is presented. The one-dimensional model is used for determining the flow characteristics in the entire setup duct, and the three-dimensional model is used for studying the current layer dynamics in the MHD channel. Computations have enabled the elucidation of flow structure and of the peculiarities of current layer formation.

This paper deals with wall shear stress in an upward gas-liquid slug flow inside a vertical tube. Local characteristics were measured by the electrodiffusion method. The method of conditional averaging over realization ensemble was used, and this allows distinguishing large-scale structures on the background of turbulent pulsation of liquid. While averaging, each slug velocity measured by a double probe of electric conductivity was taken into account. Averaged distributions of shear stress over the wall under a gas slug were obtained for different mode parameters.

Two different mechanisms responsible for the were revealed impact of gas bubbl injected into a boundary layer on the shear stress on the wetted surfaces. Both mechanisms exist due to extremely high sensitivity of bubbles even to very low pressure gradients and due to a high value of the virtual mass and coefficient of viscous drag for bubbles. The first mechanism manifests itself at the interaction of vortex structures with bubbles in the near-wall layer y⁺ < 250. The second mechanism is due to pressure gradient along the wetted surface. Ascertainment of these mechanisms explains the known discrepancies in the experimental results on gas saturation obtained on different experimental setups.