Doklady Physics最新文献

The paper is devoted to the problems of the immersion (classical) method of electrolytic plasma processing. The immersion method is compared with the jet version. The advantages of the jet version of the plasma electrolytic processing unit are revealed, which, for comparative analysis, was used to polish parts of aircraft engines made of heat-resistant alloys. An alternative version of the plasma electrolytic processing technology showed higher selectivity, versatility, and mitigating of the disadvantages of the classic version.

The article presents the results of heat transfer modeling in the in-cylinder part of a piston combined diesel engine using the AVL BOOST commercial package at the design stage. The calculation results are compared with the results of bench tests of the R6ChN 13.2/15.8 diesel engine. Heat transfer similarity equations for calculating heat loss in the cylinder-piston section of a diesel engine are recommended.

The thermal expansion coefficients of fish oil were measured in a heat-conducting calorimeter in the temperature range of 298–363 K and pressures of 0.098–49 MPa. Based on the obtained values of the coefficients of thermal expansion, the density of fish oil was calculated.

An approach to transparent monolithic polycarbonate fracture diagnostics based on the piezoelectric effect is considered. It was shown that the ΔU/U parameter decreases by at least 10 times before the polycarbonate sample begins to be destroyed. It was shown that the electrodes location influence the changes in the piezoelectric voltage. The location of electrodes along the edge of the sample can provide the best conformity between the piezoelectric voltage and the reaction force of the sample to bending deformation.

The results of an experimental study of the swelling of SEVA-113 and polycarbonate polymers in supercritical carbon dioxide are presented. The effects of temperature and pressure on the character of swelling of the selected polymers in supercritical carbon dioxide has been established. The results of joint dispersion of polymer mixtures of EVA and polycarbonate are presented.

The results of an experimental study of the solubility of the polymers SEVA-113 and SKN-18 in organic solvents in the temperature range from 26 to 60°C at atmospheric pressure are presented. The optimal organic solvents have been determined. The effect of temperature on the character of solubility of the selected polymers in organic solvents has been established.

With the use of a mathematical model of large deformations of materials with elastic, plastic, and viscous properties, an analytical solution was obtained for deformation under creep conditions of a plug in a round tube with a varying pressure drop. The motion is considered taking into account the sliding of the material in the vicinity of the rigid wall of the pipe and its deformation under increasing, constant, and decreasing pressure. The displacements, reversible and irreversible deformations, and stresses at all stages of deformation, including residual deformations and stresses at full unloading, are calculated.

The expansion and collapse of a cavitation bubble during laser heating and subcooled boiling of water in the vicinity of the tip of an optical fiber (laser heating element) installed in a water-filled glass tube with two open ends is studied experimentally and numerically. Cavitation, initiated by continuous laser radiation, is accompanied by the pushing and pulling movement of the heated liquid in the tube and outside it. For the first time, it has been shown that in a tube with an installed laser heating element in a liquid flow moving behind the walls of the bubble, when it collapses at the pole of the bubble surface remote from the end, a liquid jet appears, directed through the bubble to the end of the optical fiber. The jet speeds up the process of sucking liquid into the tube.

The monolithic design of a compact bandpass filter X-band is made on the technology of multilayered printed circuit boards. Quarter-wave stripline resonators of the filter have two conductors divided by a layer of prepreg having low parameters that bond together the design. This eliminates the influence of the prepreg on the characteristics of the devices, ensuring good repeatability of filters in mass production. To increase the high-frequency stopband of the filter, one of the conductors of each resonator is cut in half by a transverse slit. The constructive sizes of the device were obtained by parametric synthesis using the electrodynamic analysis of its 3D model. The experimental data of the five-order filter are in good agreement with the electromagnetic simulation of filter of the 3D model. The experimental device has a central frequency of the passband of 10 GHz and a fractional bandwidth of 5.7%, and its dimensions and weight are 18.0 × 5.4 × 2.1 mm³ and 0.5 g. The important advantage of the developed design is the possibility of its installation on the board using the surface mounting method.