Asymptotic behavior of high-Reynolds-number flow through an array of blunt bodies

A previously developed theory of high-Reynolds-number flow around a body is extended to the case of flow through an array of bodies. An asymptotic expansion suitable for H1 and Re1, where 2H is the spacing of the array and Re is the Reynolds number, is constructed. The results are compared to numerical calculations. The structure of the asymptotic solution for H=O(1) is discussed.Institute of Mechanics, Moscow State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 30–52, April, 1993.     

Inhibiting effect of 6-methyluracil derivatives on the free -radical oxidation of 1,4-dioxane

The antioxidation activity of 5-substituted 6-methyluracils was quantitatively estimated in the model system of initiated radical-chain oxidation of 1,4-dioxane. The rate constants of the reactions of 1,4-dioxane peroxide radicals with 6-methyluracil (1), 6-methyl-5-piperidinouracil (2), 6-methyl-5-morpholinomethyluracil (3), 6-methyl-5-morpholinouracil (4), 6-methyl-5-methylaminouracil (5), 5-ethylamino-6-methyluracil (6), and 5-hydroxy-6-methyluracil (7) were measured. Among compounds 1–7, derivative 7 is most efficient with an inhibition rate constant of (5.2±0.1) · 10⁴ L mol^-1 s^-1 (60 °C).     

Numerical Nonlinear Elastic Analysis of Orthotropic Spherical Shells with an Elliptic Cutout

Study is made of how the nonlinear properties of orthotropic composites and the ellipticity of an opening affect the stress–strain state of thin spherical shells subjected to internal pressure. An analysis of numerical results reveals compression on the inside surface of the shell near the broad of the elliptical opening. It is pointed out that as the ellipticity increases, the deformation process near the opening transforms from uniform tension and bending, typical of a shell with a circular opening, to dominated tension near the narrow of the opening and to dominated bending near the broad.     

Elastoplastic state of nonshallow flexible ellipsoidal shells under concentric loading

The elastoplastic stress-strain state of flexible ellipsoidal shells under concentric loading is investigated by the solution of nonlinear boundary-value problems. Numerical results are presented for open shells in the case of a free (unsupported) edge and a shell with a central opening (the periphery of the opening is supported by a thin ring). Solutions of the problems in linear and nonlinear statements are analyzed. Numerical results for ellipsoidal and spherical shells are compared. S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Prikladnaya Mekhanika, Vol. 35, No. 4, pp. 54–60, April, 1999.     

Stress state around holes in orthotropic cylindrical shells with allowance for nonlinearly elastic material properties

Mechanics Institute, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 10, pp. 73–77, October, 1991.     

Identification of a laminar-turbulent interface in partially turbulent flow

Viscous incompressible fluid flow along the clearance between two parallel eccentric circular cylinders is studied numerically. The geometric parameters and the Reynolds number are taken so that the turbulent flow regime takes place in a part of flow, namely, in the zone where the clearance is wide, while the low is laminar in the narrow clearance zone. Criteria using which these zones can be distinguished are discussed.     

Theoretical and experimental study of the elastoplastic state of cylindrical shells with rigid inclusions

A study is made of the stress distribution around a rigid circular inclusion on the lateral surface of a cylindrical shell subjected to a uniformly distributed load. The stress distribution present during the elastoplastic stage of deformation of the shell material is studied. Calculated results are obtained on the basis of the numerical solution of inelastic problems in accordance with the theory of thin shells and the strain theory of plasticity for the case of active loading. Experimental data for shells loaded by internal pressure are obtained with the use of pneumatic gauges. The data are in the form of values of the strains and changes in curvature in characteristic sections of the shell. The theoretical and experimental results are compared and analyzed.Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 18, pp. 72–76, 1987.