共查询到20条相似文献,搜索用时 109 毫秒
1.
A. L. Tukmakov 《Journal of Applied Mechanics and Technical Physics》2000,41(1):171-175
The dynamic instability and nonlinear behavior of a nonshallow thin elastic cylindrical panel with simply supported rectilinear
edges under uniformly distributed periodic load is studied. The regions of regular and chaotic dynamics are determined for
symmetric and nonsymmetric bending modes of the panel. It is shown that depending on the external load frequency, the nonsymmetric
buckling. which occurs when the load amplitude reaches a critical value, can lead to two different dynamic modes.
Institute of Mechanics and Mechanical Engineering, Kazan' Science Center, Russian Academy of Sciences, Kazan' 420111. Translated
from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 1, pp. 186–191, January–February, 2000. 相似文献
2.
L. M. Zigangareeva O. M. Kiselev 《Journal of Applied Mechanics and Technical Physics》1998,39(5):744-752
The problems in the construction of bodies which, satisfying some geometric limitations, are exposed to a plane symmetric
flow of a perfect (inviscid and heat-nonconducting) gas with a maximum critical Mach numberM* are considered. Solutions are found by a numerical-analytical method with the use of the variables of the velocity hodograph.
The Mach numberM* is found as a function of the geometric characteristics of the sought bodies on the basis of approximation of numerical
data.
Institute of Mathematics and Mechanics at the Kazan' State University, Kazan' 420008. Translated from Prikladnaya Mekhanika
i Tekhnicheskaya Fizika, Vol. 39, No. 5, pp. 106–115, September–October, 1998. 相似文献
3.
Near-resonance highly nonlinear ideal perfect gas oscillations in tubes are studied numerically for boundary conditions of
various types. The oscillations are initiated by weak periodic perturbations at one end of the tube. As distinct from earlier
studies [1–10], the oscillation amplitudes were not assumed to be small and the entropy increase at the shock waves formed
was taken into account. Periodic flow regimes result as a limit of the solution of a Cauchy problem for one-dimensional time-dependent
gasdynamic equations. The frequency responses of the oscillations under consideration are determined for boundary conditions
of various types. It is shown that in specific cases the attainment of a periodic regime is accompanied by the appearance
of long-wave modulations. The “repeated resonance” effect is revealed. This is due to the change in the tube's natural acoustic
frequency, which takes place during the heating of the gas in the tube by the shock waves traveling in it.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 150–157, July–August, 1994. 相似文献
4.
In this paper the following problem is solved in the linear approximation. Let a flat plate separate two uniform inviscid
fluid flows with different steady-state densities and velocities. These flows are subject to small time-dependent disturbances
due to plate deformation. This problem is solved for arbitrary deformations as well as in the case of the angular harmonic
oscillations of a flapping mover. The time-dependent forces acting on the plate are determined, together with the dynamic
characteristics of the mover and the position of the fluid-fluid interface.
Kazan'. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 55–64, January–February,
1994. 相似文献
5.
A. L. Adrianov A. A. Bezrukov Yu. A. Gaponenko 《Journal of Applied Mechanics and Technical Physics》2000,41(4):670-675
Various regimes of interaction of an axisymmetric supersonic underexpanded jet of a gas with both a finite and an infinite
planar target are studied numcrically. The model of an idcal perfect gas and one variant of Godunov's highly accurate scheme
are used. The calculated and experimental frequency spectra of pressure oscillations in the center of the target are compared:
their good agreement is obscrved.
Institute of Numerical Simulation. Siberian Division, Russian Academy of Sciences. 660036 Krasuoyarsk. Translated from Prikladnaya
Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 4, pp. 106–111, July–August, 2000. 相似文献
6.
I. G. Teregulov Yu. I. Butenko R. A. Kayumov D. Kh. Safiullin K. P. Alekseev 《Journal of Applied Mechanics and Technical Physics》1996,37(6):917-925
Kazan' State Architect-Building Academy, Kazan' 420043. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol.
37, No. 6, pp. 170–180, November–December, 1996. 相似文献
7.
V. A. Chugunov L. D. Eskin S. L. Tonkonog 《Journal of Applied Mechanics and Technical Physics》2000,41(2):267-272
The problem of exhaustion of a thin film of a non-Newtonian fluid with a power rheological law from a slotted orifice is solved
with account of film slipping relative to the underlying surface. By the method of group analysis with transformation of the
parameters entering the problem, an asymptotic formula for the film profile is obtained and a law of motion of the film edge
with small slipping is derived.
Kazan' State University, 420008 Kazan'. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 2, pp.
71–76, March–April, 2000. 相似文献
8.
A linear and nonlinear analysis of the distributed oscillations of an elastic tube with a fluid flowing in it is developed.
The critical flow velocity and the wavelength and oscillation frequency in the tube-flow system at loss of stability are found.
The geometrical and physical nonlinearities, the latter related to increase in the Young’s modulus of the tube wall material
with increasing strain, are considered. It is shown that four characteristic regimes of change of tube shape are possible:
local dilatation, collapse, flexure, and distributed auto-oscillations. The tube oscillations are analyzed numerically for
the nonaxisymmetric case. The conditions of existence of these effects in blood vessels are examined.
Nizhni Novgorod, e-mail: klochkov@appl.sci-nnov.ru. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti
i Gaza, No. 4, pp. 46–55, July–August, 2000.
The work was supported by the Russian Foundation for Basic Research (project No. 97-02-18612). 相似文献
9.
R. I. Nigmatulin I. Sh. Akhatov N. K. Vakhitova 《Journal of Applied Mechanics and Technical Physics》1999,40(2):285-291
A spherically symmetric problem of oscillations of a single gas bubble at the center of a spherical flask filled with a compressible
liquid under the action of pressure oscillations on the flask wall is considered. A system of differential-difference equations
is obtained that extends the Rayleigh-Plesset equation to the case of a compressible liquid and takes into account the pressure-wave
reflection from the bubble and the flask wall. A linear analysis of solutions of this system of equations is performed for
the case of harmonic oscillations of the bubble. Nonlinear resonance oscillations and nearly resonance nonharmonic oscillations
of the bubble caused by harmonic pressure oscillations on the flask wall are analyzed.
Ufa Scientific Center, Russian Academy of Sciences, Ufa 450000. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika,
Vol. 40, No. 2, pp. 111–118, March–April, 1999. 相似文献
10.
We investigate the effect of delay in feedback on the oscillation characteristics (amplitude and frequency) of a string generator,
which, as is well known, works in a self-induced oscillation mode and is a part of a string accelerometer (a device for measuring
the acceleration of ballistic missiles, launch vehicles, and other moving objects). A mathematical model of the dynamics of
a string generator is taken in the form of a quasilinear second-order hyperbolic equation with constant delay with respect
to one of independent variables (time). For the analysis of the mathematical model, we use the one-frequency asymptotic Krylov-Bogolyubov-Mitropol'skii
method (its first and second approximations) of nonlinear mechanics. We show that an increase in the delay in the nonlinear
feedback amplifier results in a decrease in the frequency of self-induced oscillations, which transforms the string generator
into a low-frequency device.
__________
Translated from Neliniini Kolyvannya, Vol. 11, No. 2, pp. 168–190, April–June, 2008. 相似文献
11.
S. V. Sukhinin 《Fluid Dynamics》2000,35(2):297-309
A model for the aeroacoustic resonance effects (aeolian tones) excited around a plate cascade in a gas flow is suggested.
Methods of calculating the frequencies of natural acoustic oscillations near the cascade are developed. The effect of the
cascade geometry and the Mach number of the main flow on the frequencies, abundance, and modes of the natural oscillations
is investigated. Anomalous acoustic oscillations near a cyclic plate cascade are shown to exist and are studied. It is shown
that there always exist no less than two natural oscillation frequencies in the gas flow near any nontrivial cyclic plate
cascade. It has been found that the natural oscillation frequencies can be combined in bundles such that in the case where
the number of plates in a period is large the frequencies pertaining to each bundle occupy a certain interval with arbitrary
density. The natural oscillations are classified with respect to the form of the eigenfunctions; the classification is based
on the theory of representations of groups of locally plane symmetries of the cyclic plate cascade in the solution space.
The correctness of the proposed model of the aeroacoustic resonance effects (aeolian tones) excited near a plate cascade in
a gas flow is supported by a comparison with the available experimental and theoretical data. On the basis of the investigation
performed, some previously unknown physical phenomena are predicted. Thus, the existence of frequency zones or main-flow Mach
number ranges on which aeroacoustic resonance phenomena exist near a cyclic cascade with a large number of plates in a period
is proved; it is shown that for certain frequencies of the natural oscillations near the cyclic plate cascade the resonance
oscillations may be localized in the vicinity of the source; and the existence of narrow-band wave packets slowly propagating
along the cascade is demonstrated.
Novosibirsk, e-mail: sukhinin@hydro.nsc.ru. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza,
No. 2, pp. 171–186, March–April, 2000. 相似文献
12.
S. V. Sukhinin 《Journal of Applied Mechanics and Technical Physics》1998,39(2):228-238
Acoustic eigenoscillations of a gas near a plate in a rectangular channel, i.e., the eigenfrequency of oscillations as a function
of the chord length and the position of the plate in the channel, and the form of the eigenfunctions are studied in a two-dimensional
formulation. A mathematical model of eigenoscillations near a plate in a channel has been proposed and substantiated, and
the dependence of the eigenfrequency of oscillations on the geometric parameters is studied numerically with the use of this
model.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 2, pp. 78–90, March–April, 1998. 相似文献
13.
Soluble vapor-gas bubbles performing small radial oscillations in a liquid are considered. The heat- and mass-transfer processes
and temperature and concentration inhomogeneities in the vaporgas mixture are taken into account. Expressions for the damping
rate of radial oscillations of soluble vapor-gas bubbles are obtained. In [1–3] the dynamics of vapor-gas bubble oscillations
were considered for a gas insoluble in liquid. 相似文献
14.
R. G. Galiullin É. R. Galiullina E. I. Permyakov 《Journal of Applied Mechanics and Technical Physics》1998,39(3):404-410
An analytical theory of resonant oscillations of a gas in an open-ended tube is developed. The gas flow in the tube is assumed
to be turbulent. A model of gas flow near the open end of the tube is constructed. This model allows a boundary condition
that is free of empirical parameters to be obtained. Theoretical results are in reasonable agreement with experimental data
obtained by other authors.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 3, pp. 92–99, May–June, 1998. 相似文献
15.
S. V. Sukhinin S. P. Bardakhanov 《Journal of Applied Mechanics and Technical Physics》1998,39(2):220-227
The conditions of the onset of aeroacoustic resonance phenomena near a plate in a gas flow in a rectangular channel are studied
theoretically and experimentally in a two-dimensional formulation. The eigenfrequency as a function of the plate's chord and
its position in the channel, the shape of the eigenfunctions, and the effect of the Mach number of the basic gas flow versus
the eigenfrequencies and eigenfunctions and the mechanism of self-excited oscillations are determined. A mathematical model
by means of which the dependence of the resonance phenomena on the geometrical parameters of the structure were performed
is proposed and substantiated.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 2, pp. 69–77, March–April, 1998. 相似文献
16.
Andrew Belmonte 《Rheologica Acta》2000,39(6):554-559
Observations of the motion of a rising bubble in a wormlike micellar system are presented, obtained in both a rotating toroidal
cell and a stationary box. For equimolar concentrations of aqueous CTAB/NaSal (8–11 mM), bubbles larger than a certain volume
undergo oscillations in shape which include an apparent cusp. The average frequency of these oscillations is found to increase
with bubble volume.
Received: 12 November 1999 Accepted: 5 April 2000 相似文献
17.
In this paper, the stability of an umbilical–ROV system under nonlinear oscillations in heave motion is analyzed using numerical
methods for the uncontrolled and controlled cases comparatively. Mainly the appearance of the so-called taut–slack phenomenon
on the umbilical cable produced by interactions of monochromatic waves and an operated ROV is specially focused. Nonlinear
elements were considered as nonlinear drag damping, bilinear restoring force and saturation of the actuators. Free-of-taut/slack
stability regions are investigated in a space of physical bifurcation parameters involving a set of both operation and design
parameters. They indicate a wide diversity in qualitative behaviors, both in the periodicity and possible routes to chaos
from the stability regions to outside. For detection of periodicity of the nonlinear oscillations inside and outside the stability
regions, a method based on Cauchy series is developed. The first part of the results is dedicated to the stability of the
uncontrolled dynamics. These results suggest the design of a control system that is able to counteract hefty hauls of the
cable during the sinking/lifting operation under perturbation. A combination of a force and cinematic controller based on
nonlinear model–reference control is proposed. Through a comparative study of the stability regions for uncontrolled and controlled
dynamics, it is shown that the control system can extend considerably these regions without appearance of the taut–slack phenomenon
despite the presence of wave perturbations. The limits between the taut and taut–slack zones are defined by the wave steepness
and the available energy of the actuators. 相似文献
18.
Nonlinear gas oscillations in a closed tube driven by the aperiodic motions of a piston as a result of the action of the external
and internal pressure drop are studied. The external pressure takes two values alternating at the moment of change of direction
of motion of the piston. Two models of the motion of the gas are considered. Model 1 is formed by a system of equations representing
the mass, momentum, and entropy conservation laws. As distinct from model 1, model 2 includes the total energy conservation
law in place of the entropy conservation laws.
Kazan’. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 134–142, March–April, 1998.
The work was carried out with partial support from the Russian Foundation for Fundamental Research (project No. 96-01-00484). 相似文献
19.
Flow law constraints that make it possible to establish comparison theorems (analogs of the theorems of [1, 2]) for nonlinear
flows in an anisotropic inhomogeneous medium are formulated. In the theorems obtained the changes in the values of the pressure
head and, moreover, the flow rate, filter velocity and pressure head gradients for such perturbations of the problem as the
depression of individual surfaces, changes in the given boundary values of the head, etc., are established. The strict monotonicity
of the relation between the flow rate and the pressure head difference in a region of the enlarged stream tube type and the
possibility of an increase in flow rate with increase in flow resistance are demonstrated. The question of the correspondence
between the constraints introduced and certain common models of porous media is discussed.
Kazan'. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 45–51, September–October, 1988. 相似文献
20.
The possibility of controlling the oscillations of a spherical gas bubble in an ideal incompressible liquid is subjected to
theoretical analysis. Liquid surface tension forces are not taken into account. The optimization process realizing a maximum
of the radius amplitude and a maximum of the gas pressure in the bubble for a given impulsive change of pressure at infinity
is considered. A shock-resonance bubble oscillation procedure giving stepwise pressure changes at the extrema of the radius
is constructed. This problem is of interest in connection with the investigation of cavitation erosion [1] and processes in
biological tissues [2–4].
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 175–178, September–October, 1988. 相似文献