Home – Home – Jornals – Thermophysics and Aeromechanics 2007 number 1

On May 18, 1957, the Soviet Government adopted a decree about establishing the Siberian Branch of the Academy of Sciences (SB AS USSR). The initiative for this historical decision was backed up by several prominent scientists: academicians M.A. Lavrentyev, S.A. Khristianovich, and S.L. Sobolev. They promoted the idea of creating a new territorial division of Academy and supported this idea by personal decision to reallocate it from the capital to Siberia together with their scientific schools.

Sergey Alekseevich Khristianovich is one of the famous Russian mechanical engineers of the 20^th century together with N.E. Zhukovsky, S.A. Chaplygin, N.E. Kochin, and others. He made an immense contribution to some aspects of mechanics, such as aerogasdynamics, rock mechanics, theory of plasticity, filtration theory, and environmental power engineering. All this was preceded by a long, hard, and fruitful life full of outstanding events.

I remember my first encounter with S.S. Kutateladze; this was at the All-Union Conference on Self-Similarity Theory in the conference hall of the Krzhizhanovsky Power Engineering Institute of the USSR Academy of Sciences. The young generation of researchers occupied the balcony places. I remember a bright lecture of young S.S. Kutateladze, who became our

The processes of breaking, solution, and formation of hydrates behind a shock wave of moderate amplitude were studied experimentally in water with carbon dioxide bubbles under different initial static pressures. It is shown that an increase in the static pressure in a gas-liquid medium leads to reduction of critical relative amplitude of the shock wave, corresponding to starting development of Kelvin ¾ Helmholtz instability and bubble splitting into small gas inclusions behind the shock wave front. It is shown that the rates of carbon dioxide solution and hydrate formation behind the shock wave front are close by the value; their dependences on medium and wave parameters are determined. Calculations by the model of gas hydration behind the shock wave are presented.

The dynamics and heat and mass exchange in the pressure wave of a vapor bubble containing a hot particle was investigated parametrically. The influence of the particle size and temperature, of the liquid temperature and static pressure, and the wave amplitude on the dynamics of such a two-phase bubble was studied. A procedure is proposed to estimate the least value of the thickness of a vapor layer around the particle.

Experiments were carried out on ultrasonic cavitation in glycerin. The zone near the emitter has a structure from interacting gas-vapor bubbles; this structure takes the form of fractal clusters. The photometry of passed laser emission was the tool for studying dynamics of fluctuations. In transitive mode, the power spectrum of fluctuation varies by the law inversely proportional to frequency. Distributions of local fluctuations are different from Gaussian and exhibit the property of scale invariance. The qualitative behavior of the frequency dependence of the spectral fluctuation density was tested while varying the power of the ultrasonic emitter. It was demonstrated that the growth of the high-frequency margin of flicker-type behavior evidences for growing instability and can be considered as a forerunner of possible large-scale outbursts.

This paper deals with experimental results on flowboiling heat transfer of liquid moving in an annular channel with unilateral central heating under the conditions of a significant effect of capillary forces on the flow modes and heat transfer . Experiments were carried out on boiling freon R318

Thermal conductivity of liquid ozone-safe refrigerant R404A was studied for the first time in the range of temperatures of 297.9

Wave characteristics of the water film flow over a vertical plate with a heater were studied. Without a heat flux, data obtained perfectly coincide with results of other authors obtained for an isothermal liquid film. When heating the falling liquid, thermocapillary forces form the rivulets and thin film between them. It was found out that an increase in the heat flux causes a rise of the phase velocity and decreases the frequency of 3D waves. It is shown that in contrast to the known data for an isothermal liquid film, the average relative wave amplitude increases with a rise of dimensionless complex Re_loc/at relatively high heat flux densities in the interrivulet. The growth of wave amplitude under the action of thermocapillary forces was revealed in the interrivulet, what corresponds to calculations.

The temperature variations of the density of liquid magnesium-lead alloys were measured by the gamma-method in the temperature range from the liquidus temperature to 950- 1000 K for compositions of 19.11, 33.45, 52.46, and 83.06 at. % Pb. It is shown that within the estimated errors (0.25- 0.30 %), the alloy density depends linearly on the temperature. Approximation dependences r (T) were obtained for every studied composition together with generalizing density-temperature and density-concentration dependences for the range of 0- 100 at. % Pb.

The passive systems for ensuring the thermal regime of space objects, which are in current use, can preserve the temperature at the same level only under a certain orientation of spacecraft and at a constant heat release of the equipment. At a variable orientation of the space object, its temperature may vary due to a possible illumination of the radiator-emitter of the system for ensuring the thermal regime by the solar or planet radiation. At a variable heat release the object temperature changes due to an off-design regime of the radiator operation. To compensate for the given effects the active elements are used ¾ the heaters and coolers. This reduces the reliability of thermal regulation system and, consequently, the reliability of the entire spacecraft.

A comparative analysis of the aerogasdynamics of waveriders designed from two different flow types, namely the axisymmetric conical flows and the flows behind two-dimensional planar shocks, was carried out. Integral aerodynamic characteristics of a configuration with different forms of transverse contours of the lower surface were considered, and the

The questions related to the formulation and numerical realization of boundary conditions on a wall at the computation of turbulent flows on unstructured grids are considered. A technique is proposed for realization of weak boundary conditions assuming a non-zero value of the tangent velocity on the wall at a discretization of the Reynolds-averaged Navier - Stokes equations by the control volume method. The capabilities of the developed approach are demonstrated by the example of computing the flow in the inter-blade channel of a low-velocity compressor. The influence of the near-wall grid step on the accuracy of computations, in particular, the pressure distribution near the profile trailing edge is shown, and the solution grid dependence is investigated when using the method of near-wall functions and weak boundary conditions.

Hot-wire measurements have been undertaken in a turbulent boundary layer which is subjected to an impulse in form of a short roughness strip with the aim of examining its influence on the structure of the turbulent boundary layer. The results indicate that, while the energy containing motion is shifted from low wave number to high wave number near the wall due to the interfering of the roughness strip with the near-wall structure, the reverse is the case in the outer region. While the anisotropy at small scale changes appreciably, there is no discernable change at the large scale when distance from the wall is increased as reflected in the collapses of spectra shear correlation coefficient at the low wave number. It further shows that the roughness strip alters the flow dynamics of the boundary layer as shown in the changes in the mixing length distribution.

Measurement results on turbulent friction are presented for nine single-layer compliant coatings in comparison with a polished solid surface streamlined by the water flow. Three experimental series separated by time passed after coating fabrication were carried out. Results on monitoring of the viscoelastic properties of coating materials are shown; they allow analysing coating aging effect as the instability factor of coating hydrodynamic efficiency.

A complex numerical and experimental investigation of burner devices for a reburning of the anode gas of aluminum production was carried out. The chosen mathematical model of the processes of aerodynamics, heat exchange, and gas burning was identified and adapted on the basis of data of real-scale measurements. Basing on computational experiments the optimization of the design of elements of the system for anode gas detoxication and transport was carried out. A new system was proposed and tested for reburning the anode gases of electrolysis production, which consists of an improved burner device and a dust-sedimenting chamber with a possibility of regulating the amount of gas suction.