Uniaxial waves in randomly heterogeneous elastic media

Propagation of uniaxial sound waves in heterogeneous linear elastic one-dimensional media is considered. The scalar wave equation is transformed by the Liouville substitution and the Dyson integral equation is applied for a statistically homogeneous field of heterogeneities that results in an integral spatial representation for the mean wave field. The mean field is analysed in detail for the following three correlation functions: (i) an exponential one; (ii) a mean-square differentiable correlation function with a hidden periodicity; and (iii) a non-differentiable correlation function with a hidden periodicity. Despite the variety of the stochastic properties of the media, the equation for the mean field takes formally the same form for the three cases. For this reason, the general case of the random elastic medium with an arbitrary heterogeneity of small scale is considered and simple closed form expressions for the mean field and attenuation are derived. Applicability of the modelling of extended complex engineering structures by one-dimensional random media is discussed. The overall mechanical parameters of the primary structure and the secondary systems determine average rigidity, average mass density and average wave speed, while the secondary systems determine the attenuation. The latter is shown to depend upon the size and range of the secondary systems.     

Optimal design of roller beds

Examples are cited for analyses of optimal structural parameters of a roller bed in developing a structure of uniform strength with minimal metal consumption. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 1, pp. 6–7, January, 2006.     

Displacement of igniter and specimen materials in combustion of gas-free systems in a rigid shell

We present results from an investigation into the burning of a gas-free Ti + C system (diluted to 20% with titanium carbide), this system contained in combination with an igniter tablet fabricated out of a Cr₂O₃ + 2Al + 4B mixture in a rigid shell. We have demonstrated that the burning is accompanied by displacement of the material through the appearance of a decompression wave (a sharp reduction in density in the vicinity of the combustion front), thus leading to a change in the burning velocity.Moscow. Translated from Fizika Goreniya i Vzryva, No. 2, pp. 94–97, March–April, 1991.     

Comparative study of thermodynamic efficiencies of evaporation schemes in capillary structures

A. M. Gor'kii Ural State University, Ekaterinburg. Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 62, No. 2, pp. 173–179, February, 1992.     

Condition of the beginning of vibrational gas combustion in an unsealed vessel of rectangular shape

Moscow. Translated from Fizika Goreniya i Vzryva, Vol 25, No. 1, pp. 36–39, January–February, 1989.     

The Calibration of Large Vertical Cylindrical Tanks by a Geometrical Method

A comparative analysis of the MI 1823-87, GOST 8.570-2000 and ISO 7507 standards, which regulate the geometric methods of calibrating large vertical cylindrical tanks is presented.     

Comparison of Standards for Calculating Flow Rate and Amount with ISO Standards

ISO documents and standards are compared for calculating flow rates and amounts on the basis of gas distribution data for Moscow region. It is shown to be best to introduce Changes 1 into MI 2588-2000, which have been accepted by most of the TC 30 countries.     

Test facility for investigation of heat transfer of promising coolants for the nuclear power industry

The results are presented of experimental investigations into liquid metal heat transfer performed by the joint research group consisting of specialist in heat transfer and hydrodynamics from NIU MPEI and JIHT RAS. The program of experiments has been prepared considering the concept of development of the nuclear power industry in Russia. This concept calls for, in addition to extensive application of water-cooled, water-moderated (VVER-type) power reactors and BN-type sodium cooled fast reactors, development of the new generation of BREST-type reactors, fusion power reactors, and thermonuclear neutron sources. The basic coolants for these nuclear power installations will be heavy liquid metals, such as lead and lithium-lead alloy. The team of specialists from NRU MPEI and JIHT RAS commissioned a new RK-3 mercury MHD-test facility. The major components of this test facility are a unique electrical magnet constructed at Budker Nuclear Physics Institute and a pressurized liquid metal circuit. The test facility is designed for investigating upward and downward liquid metal flows in channels of various cross-sections in a transverse magnetic field. A probe procedure will be used for experimental investigation into heat transfer and hydrodynamics as well as for measuring temperature, velocity, and flow parameter fluctuations. It is generally adopted that liquid metals are the best coolants for the Tokamak reactors. However, alternative coolants should be sought for. As an alternative to liquid metal coolants, molten salts, such as fluorides of lithium and beryllium (so-called FLiBes) or fluorides of alkali metals (so-called FLiNaK) doped with uranium fluoride, can be used. That is why the team of specialists from NRU MPEI and JIHT RAS, in parallel with development of a mercury MHD test facility, is designing a test facility for simulating molten salt heat transfer and hydrodynamics. Since development of this test facility requires numerical predictions and verification of numerical codes, all examined configurations of the MHD flow are also investigated numerically.