Strength analysis of a split sleeve in a pipe containing a defect

We study the decrease in the strength of a pipe containing an artificial defect. On the basis of the analytic and numerical models, we consider the influence of the structural features of a split sleeve on its load-carrying ability. We also analyze the joint operation of a sleeve and a pipe containing an artificially made axial surface defect. The results of the numerical analysis are compared with the experimental data. Translated from Problemy Prochnosti, No. 2, pp. 102–111, March–April, 2009.     

Stress analysis of a strip with a step and a crack

Stress analysis for a strip of which widths are different at the right and left handsides is carried out for before and after occurrence of a crack at a corner of a step. The strip is analyzed as a thin plate bending problem subject to transverse bending and torsion, and as a plane eleastic problem subject to bending in the plane and uniaxial tension. The rational mapping function of a sum of fractional expressions and complex variable method are used. Stress distribution and stress intensity factors are obtained.     

Resistance of a sphere in a slow flow of a viscoelastic fluid

The authors have obtained an approximate solution of the problem of the resistance of a rigid sphere in a slow flow of a Maxwell viscoelastic fluid that is in good agreement with experimental data [1] for Weissenberg numbers We ≤ 0.7. It is shown that the effect of a decrease in the coefficient of resistance of a sphere in the interval 0.1 ≤ We ≤ 0.7 established experimentally is determined in full measure by the linear viscoelastic properties of the Maxwell fluid. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 71, No. 6, pp. 1138–1140, November–December, 1998.     

Imaging a point to a line with a single spherical mirror

Methods for imaging a single point source to a line image are discussed, and a design study of single spherical mirror systems that form aberration-free line images is presented. An expression forthe ray density along the line image is derived for such systems in the cases of (i) uniform beam profiles and (ii) Gaussian beam profiles. The resulting ray density profiles are illustrated for single spherical mirror systems over a wide range of design parameters.     

Interaction between a cylindrical shell in a fluid and a pulsating bubble

The dynamic behavior of a cylindrical fluid-immersed shell in a pressure wave initiated by a pulsating vapor-gas bubble that develops as a result of the action of laser radiation on the absorbing medium (metal) is examined experimentally and theoretically. The results of the experiments suggest that the amplitude of the shock wave that develops as a result of complete or partial vaporization of the absorbing medium is appreciably smaller than the amplitude of the waves due to pulsations of the bubble that is formed. Experimental data on the pattern of structural deformation are confirmed by calculations. The effect of load simulation on the behavior of the shell is established according to computational data.Translated from Problemy Prochnosti, No. 6, pp. 116–120, June, 1990.     

Analysis of a Premature Failure of a Hub from a Diesel Generator of a High-Speed Motor Ship

Failure analysis is carried out on a fractured hub obtained from a diesel generator of a high-speed motor ship. Macrofractography, microfractography, standard optical metallography, material characterization techniques, and numerical modeling were used to verify the findings of the current investigation. Cracking initiation is attributed to fretting fatigue caused by a modification performed in the vicinity of the fractured hub. Operational vibrations contributed to the propagation of the cracks as typical fatigue cracks until final fracture.     

Interaction of a characteristic shock with a weak discontinuity in a relaxing gas

The evolution of a characteristic shock in a relaxing gas is investigated and its interaction with a weak discontinuity is studied. A particular solution to the governing system, which exhibits space–time dependence, is used to study the evolutionary behaviour of the characteristic shock; the properties of incident, reflected and transmitted waves, influenced by the relaxation mechanism, together with the geometry of the fluid flow and the background state at the rear of the shock, are studied.     

Diffusion of a dissolved gas in a flow with a stationary cavity

An exact solution is obtained for the plane problem of the diffusion of a gas from a solution into a stationary cavity behind a symmetric profile for a zero cavitation number in an ideal liquid, and its approximate generalizations are indicated.     

Eddy-current interaction of a long coil with a slot in a conductive plate

We describe a truncated-domain method for calculating eddy currents in a plate with a long flaw. The plate is modeled as a conductive half-space and the flaw is a long slot with a rectangular cross section. A long two-dimensional (2-D) coil carrying an alternating current is aligned parallel to the slot. The coil impedance variation with frequency is determined for an arbitrary coil location. The electromagnetic field due to a long coil above a conductive half-space can be expressed as integrals of trigonometric functions. For a half-space with a long slot, however, additional boundary conditions must be satisfied at the slot walls. The truncated-domain method makes this possible by recasting the problem in a finite domain; as a result, the Fourier integral is replaced by a series. The domain can be made arbitrarily large, thereby yielding results that are numerically as close to the infinite domain solution as desired. We have used the truncated domain approach to study both eddy-current flaw interactions and edge effects in the limiting case of a very wide and deep slot. We confirmed the theoretical predictions by comparing them with results of a 2-D finite element calculation and of experiments.     

Mixing of a jet array with a transverse stream in a channel

Universal empirical formulas are proposed for calculating, from the trajectories, the attenuation of velocity and temperature along the axis of a jet through a transverse stream in a channel.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 3, pp. 541–544, September, 1972.     

Transformation of a system of differential equations of heat and mass transfer in a domain with a variable boundary into a system of equations for a domain with a fixed boundary

We present a method for transforming a system of differential equations of heat and mass transfer in a region with a variable boundary into an equivalent system of equations for a region with a fixed boundary.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 31, No. 5, pp. 873–875, November, 1976.     

Ceramesh — a company and a membrane

Claimed as a major advance in microfiltration technology, Ceramesh is an inorganic composite ceramic membrane that can be produced in a flat sheet suitable for use in process-scale crossflow filtration systems. The membrane combines a metal mesh and a ceramic to give strength, formability and both chemical and heat resistance The Ceramesh membrane technology has its origins in work carried out at Alcan Separations in Banbury and has been under development since 1988. Some of the original team had also worked on the development of the Anopore membrane, since commercialised by Anotec, and these close personal links have been maintained. Ceramesh Ltd was formed in 1990 by Alcan and a venture capital company with the aim of speeding the development of the membrane and ensuring its early introduction to the commercial filtration market. These objectives have now been achieved and by the middle of 1992 the Ceramesh membrane has been evaluated for a number of specific applications, been incorporated into a range of commercial filtration equipment, and formally launched into the chemical-process industries at the Eurochem exhibition held in Birmingham in June.     

Reminiscence of a teacher and a researcher

Abstract

The names of previous after-dinner speakers at this conference read like a Who is Who of Quantum Optics and Photonics research. When the organizers of this conference asked me to present an after-dinner talk I felt honored by the invitation, but also humbled by joining such a distinguished company. This fact gives me a “Leitmotiv” for my present talk, because being humbled by, and feeling inferior to, all the brilliant minds one encounters in one's career is a necessary occurrence, which most of the younger listeners in this audience have either experienced or will experience. I have witnessed these feelings as advisor to students at MIT. Many of them fear that everything worth doing has already been done. There is a simple answer to this. Do not get discouraged, work harder and you will also make a respectable contribution to science or engineering.     

Polarization of a neutron beam using a superconductor

Based on the London theory of superconductivity and using the quasistatic approximation, we have calculated the interaction energy between a superconducting plane and a dipole which is moving toward or away from the plane. Using the decoupling approximation, we have investigated the displacement and the angle flipping of a neutron, when the neutron moves toward or away from the superconducting plane. The theoretical model can, in principle, be applied to construct an apparatus to polarize the beam from a thermal neutron reactor.     

Heat exchange of a swirled stream of a gas suspension in a pipe

The results of an experimental investigation of heat exchange during turbulent flow of a gas containing suspended particles of a solid material in a horizontal pipe are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 2, pp. 198–202, August, 1986.     

Passage of a liquid drop through a bifurcation

Numerical simulations of the motion of a viscous liquid drop through a two-dimensional bifurcating channel are conducted using a boundary-element method for Stokes flow. The drop viscosity is assumed to be equal to the ambient fluid viscosity and the drop interface is assumed to exhibit uniform surface tension. The mean fluid pressures are prescribed at the channel inlet and two outlets, and the corresponding flow rates are computed as part of the solution. Preliminary simulations show that the shape of a two-dimensional drop moving through a channel with parallel walls is similar to that of an axisymmetric drop moving along the centerline of a circular tube. The ability of a drop to remain intact as it passes through the bifurcation is determined by the drop size and capillary number expressing the significance of surface tension. For a given drop size and channel inlet and outlet pressures, there is a critical capillary number above which a drop splits into two pieces connected by a thinning bridge. The presence of the drop has a weak effect on the inlet and outlet flow rates throughout its passage. Simulations based on a boundary-element method for a rigid particle with circular or elliptical shape reveal a significantly stronger effect due to the absence of interfacial mobility.     

Generation of a homogeneous plasma in a glow discharge with a hollow anode and a wide-aperture hollow cathode

The principles for designing electrode systems for sources of ion beams of large cross section on the basis of a glow discharge are considered, and a system with combined magnetic and electrostatic confinement of the fast electrons in a wide-aperture hollow cathode and the generation of an ion-emitting plasma in the anode cavity is proposed. It is shown that the system investigated generates a plasma with a nearly homogeneous distribution of the ion emission current density at low gas pressures and can be effectively used to obtain ion beams over a broad range of energies. Pis’ma Zh. Tekh. Fiz. 25, 83–88 (June 26, 1999)     

Performance of a circle-to-line optical system for a Fabry-Perot interferometer: a laboratory study

We describe the characterization and laboratory study of a new optical device, a circle-to-line interferometer optical (CLIO) system, for a Fabry-Perot interferometer. The CLIO system converts a circular Fabry-Perot interferometer fringe pattern into a linear fringe pattern that can be analyzed by a linear array detector or a charge-coupled device. One can achieve the circle-to-line conversion by the use of a mirrored kaleidoscope and a 90-deg segment of a 45-deg half-angle internally reflecting cone. Our laboratory results are in good agreement with theoretical predictions. The aberrations associated with this optical system are minor for large F-number optical systems, especially for the cone segment. The finesse degradation caused by this CLIO system is relatively small, which agrees with the results of a ray-trace study.     

Drag of a plate in a uniform flow of a weak polymer solution

The problem of the drag of a plate moving in a weak polymer solution is solved on the basis of a three-layer schematization of the velocity distribution in the turbulent boundary layer.Translated from Inzhenerno-Fizicheskii Zhurnal, Vo. 41, No. 5, pp. 819–826, November, 1981.