SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 813 papers in Mechanics
This paper investigates flame propagation during the predetonation period in rough tubes, focusing on hydrogen air mixtures and oxygen enriched mixtures in a semi-closed square channel with optically accessible walls. Using frame-by-frame photography, the authors distinguish three stages: initial la…
This paper examines the structure of Mach lines and weak shock-like disturbances in a relaxing medium, where the characteristics of relaxation hydrodynamics differ from those of equilibrium hydrodynamics. Using the problem of steady supersonic flow past a thin wedge, the authors solve the linearized…
This paper develops an approximate continuum model for the vertical penetration of pointed axisymmetric bodies, specifically cylindrical projectiles with conical noses, into low moisture soils represented as a plastic gas. Using dynamic compression data, shock wave propagation, mass conservation, eq…
The paper treats unsteady linear filtration of a homogeneous fluid in a circular elastic stratum of variable thickness, operated by arbitrarily located wells while constant pressure is maintained on the supply contour. By transforming the pressure with the square root of the thickness function, appl…
This paper examines the one-dimensional gas-dynamic interaction of a simple wave with a contact discontinuity, a configuration relevant to unsteady compressible flow. For adiabatic exponents of the form kappa equals (2n plus 3) divided by (2n plus 1), it formulates an exact solution in terms of a po…
The paper develops a method for approximating the coefficient in the Reynolds equation, and related elliptic or hyperbolic equations, so that their solutions can be reduced to solutions of a simpler equation with an effectively solvable boundary-value problem. Using a Darboux-type transformation, it…
This paper examines how initially homogeneous isotropic turbulence in a gas changes under rapid homogeneous deformation, such as passage through shock waves, nozzles, diffusers, or combustion zones. Assuming the deformation time is much shorter than the turbulence decay time, viscosity and inertial …
This paper treats the contact problem for an elastic layer of finite thickness acted on by an eccentric vertical force applied through a circular rigid punch. The loading is decomposed into a central force and a moment, and the solution is developed using harmonic displacement potentials, Bessel int…
This paper derives simplified governing equations for steady plane and axisymmetric ideal-gas flows at very large supersonic Mach numbers, using a small parameter related to the inverse Mach number and a hypersonic similarity parameter. It distinguishes the regime in which this parameter is of order…
This paper analyzes the linear stability of a thin viscous liquid film flowing over a solid wall under the action of a viscous gas stream. Small disturbances of the gas-liquid interface are introduced, and in the limiting case of small gas-to-liquid viscosity and density ratios the problem is reduce…
This note examines linearized three-dimensional problems in the theory of ideal plasticity, extending earlier planar treatments in which the governing relations reduced to wave equations. For a square bar with shallow smooth notches under tension, the stress perturbations are expressed through a pot…
This paper formulates and solves a finite amplitude Cauchy-Poisson problem for waves on the free surface of an infinitely deep heavy liquid bounded by vertical walls, with a prescribed initial velocity potential. Using Lagrangian variables and the Lindstedt-Poincaré method, the motion, pressure func…
This paper examines a class of coupler curves in plane four-bar mechanisms, defined not as loci of points but as envelopes of straight lines fixed in the coupler plane. It derives the family equation for such lines, expresses the relevant geometric parameter and its derivative in terms of mechanism …
This paper examines whether empirical relative permeability relations obtained for externally introduced gas-liquid mixtures can be applied to filtration of gas-saturated liquids in which gas is liberated from solution. Using linear flow experiments in uncemented sand and dimensional analysis, it co…
This paper derives exact similarity solutions for the steady melting of a semi-infinite heat-conducting solid near the forward critical point in plane and axisymmetric incompressible flow. Starting from the Navier, Stokes and heat-conduction equations for the outer fluid, melt film, and solid, with …
This paper studies the plane unsteady motion of an incompressible heavy fluid near an inclined shore whose angle with the free surface is pi divided by twice an integer. Using known standing-wave solutions, the author formulates the Cauchy-Poisson problem for an initial surface impulse and solves th…
This paper analyzes the elastic stability of a cantilever circular cylindrical shell subjected to external pressure when its movable edge is reinforced by an elastic ring. Starting from linearized shell equilibrium equations and ring equilibrium relations, the authors derive approximate governing eq…
The paper proposes a finite difference method for computing discontinuous solutions of one-dimensional gas dynamics equations with an arbitrary equation of state. The approach is a through-computation scheme that does not explicitly track discontinuity points, but it incorporates Hugoniot jump condi…
This paper proposes a numerical method for integrating laminar boundary layer equations with arbitrary boundary conditions, focusing on steady plane incompressible flow while indicating possible extension to compressible cases. The argument uses the translational invariance of the transverse coordin…
This paper investigates the stability of the water-oil contact during water displacement of oil in layered porous media using transparent two-layer and three-layer physical models. Experiments with hydrophilic ground-glass media, kerosene and water, and layer permeability ratios from 2 to 16 showed …
This paper examines compatibility equations for the finite strain tensor under simple loading, building on Sedov’s formulation of the deformation conditions associated with such loading. The equations are rewritten in a more explicit form by using the inverse metric expression and the arbitrariness …
This note investigates the postcritical elastic deformation of axially compressed cylindrical shells after loss of stability and snap-through, with the aim of qualitatively describing the transition and estimating the lower critical load. The analysis approximates the deformed middle surface by an i…
This paper examines the equilibrium and settling motion of a sphere in a viscoplastic liquid with a limiting shear stress, focusing on the critical particle diameter below which gravity cannot overcome the medium’s structural strength. Using dimensional analysis, the resistance force is expressed in…
This paper investigates how periodic bed microstructures, or ripples, form and evolve under wave flow, and how their dimensions, migration velocity, and associated sediment flux depend on wave parameters, fluid properties, and particle characteristics. Experiments in a 15 meter wave flume are used t…
The paper analyzes how a near-surface atmospheric layer with reduced vertical turbulent diffusion affects the ground deposition of a heavy admixture released instantaneously from an elevated point source, when wind speed varies with height as a polynomial. The authors solve the turbulent diffusion e…
This paper analyzes plane flow of an ideal incompressible infinitely conducting fluid past a body when the magnetic field and velocity are nearly, but not exactly, parallel at infinity. It argues that a small transverse magnetic-field component removes the surface field discontinuity present in the …
This paper examines the propagation of a strong point-explosion shock wave in an atmosphere whose density varies exponentially with height, a case in which the usual self-similar solution for a homogeneous medium no longer applies. It proposes a semi-quantitative approximation based on the near-unif…
The paper analyzes self-similar motion of a piston in an ideally conducting fluid subjected to a magnetic field of arbitrary strength, with magnetic lines of force perpendicular to the piston plane. It classifies the possible fast and slow magnetohydrodynamic shock and rarefaction waves that can pre…
This paper examines the calculation of oblique shock waves in ideal magnetic gas dynamics, focusing on how the tangential magnetic field, downstream velocity components, and density behind the shock front are obtained from related cubic equations. It distinguishes accelerated and retarded shock-wave…
This paper extends the analysis of transient regimes in continuously operating tube heat exchangers from thin separating walls to the more practical case of thick walls with finite heat capacity. Under assumptions of one-dimensional turbulent flow, rapid heat propagation through the wall, and neglig…
This paper analyzes proportional navigation for arbitrary integer values of the navigation constant, extending earlier treatments that were largely confined to the case b = 2 and often required numerical integration. The authors derive closed-form trajectory equations from the kinematic system, givi…
This paper constructs examples of oscillating motion in the Newtonian three-body problem, where two bodies remain at bounded mutual distance while a third has unbounded distance from them without tending to infinity. The argument first treats a symmetric restricted problem with two equal masses movi…
This paper examines the risk of sudden brittle fracture in structural elements subjected to cyclic loading and occasional overloads, focusing on the early stages of fatigue crack development. Experiments on medium carbon steel rectangular beams in bending compared specimens with fatigue cracks forme…
This paper extends a phenomenological theory of turbulent stresses to account for anisotropic effects observed in boundary layers and pipe flow, particularly Laufer’s measurements showing unequal normal stress components and deviations from an isotropic stress, strain-rate relation near walls. It in…
This paper generalizes hypersonic small perturbation theory to thin or elongated bodies at large angles of attack, where the usual assumption of small surface inclination is no longer applicable. By introducing scaled variables based on body slenderness, transverse free stream velocity, and high Mac…
The paper treats plane elasticity problems for an infinite strip with either prescribed boundary displacements or prescribed boundary stresses, using Kolosov, Muskhelishvili complex potentials and a conformal mapping of the strip to a half-plane. For the displacement problem, the solution is reduced…
This note develops the apparatus needed to apply the method of singularities to fluid flow calculations in radial-axial turbines of general form. It formulates the governing equations for periodic lattices of sources and vortices, reduces the source and vortex problems to analogous potential and str…
This paper analyzes subharmonic oscillations in an elastic rod with hinged ends and nonlinear inertia arising from a concentrated mass on a movable support, under a concentrated periodic transverse force. Using a single-mode approximation and Galerkin’s method, the author derives algebraic condition…
The paper studies forced finite-amplitude vibrations of a hinged rod with one elastically yielding support, governed by a nonlinear equation containing both axial elastic and inertial nonlinearities. It proposes an approximation in which the harmonic excitation is replaced by a time dependence simil…
The paper studies traveling wave solutions of rank greater than one for the equations of gas dynamics, extending the notion of simple traveling waves for quasilinear systems. For a polytropic gas, the authors derive conditions under which a rank 2 traveling wave in two spatial variables possesses th…
An exact solution is developed for a three-dimensional mixed boundary-value problem in linear elasticity for an unbounded layer, with prescribed displacements on one plane face and prescribed stresses on the other. The displacement field is represented by Papkovich-Neuber harmonic functions, and the…
This paper examines how deformation rate affects thixotropic recovery in a 2 percent aluminum naphthenate gel in vaseline oil, emphasizing the need to control both the destructive and measuring velocity gradients. The authors describe an oscillographic method for recording stress, deformation, defor…
This paper presents an experimental and theoretical study of spherical explosions in an unbounded compacting inelastic medium, using small explosive charges in sandy soil while eliminating free-surface effects. Measurements of wave-front propagation and particle displacements are used to derive empi…
This paper examines the stability of a compressed elastic circular rod using the full mathematical theory of elasticity rather than the simplifying assumptions of strength of materials. Starting from the uniformly compressed cylindrical state, it formulates infinitesimal neighboring equilibria, deri…
This paper presents a hydrodynamic method for nonlinear, nonstationary long range forecasting of planetary scale pressure fields at the middle atmospheric level. The authors formulate the problem through the spherical vorticity transport equation for the stream function, introduce an auxiliary funct…
This paper examines how nonuniform heating affects the time-dependent redistribution of stresses in parts operating under high temperature and creep conditions. Using a hardening-based creep law, it develops an incremental calculation scheme that allows for stresses of either sign and possible stres…
This paper analyzes thermoelastic stresses in a closed spherical shell subjected to a known nonuniform, spherically symmetric temperature field, allowing the Lamé coefficients, thermal expansion, and relaxation kernels to depend on temperature and time. Using generalized Volterra constitutive relati…
The paper develops asymptotic solutions for a nonlinear one degree of freedom oscillatory system with slowly varying parameters and weak dissipation, over time intervals of order 1 divided by the small parameter. Using the method of standard equations, the solution is represented through a periodic …
This paper examines the scale effect in ice, whereby larger specimens show lower calculated flexural strength than smaller ones, and argues that existing explanations do not adequately match experiment. It proposes a fracture model in which failure begins at the weakest defect in the extreme tensile…
