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1.
2.
L. M. Davydov 《Fluid Dynamics》1987,22(1):149-151
In order to predict the propagation of an impurity and water quality on a shelf it is necessary to know the water mass dynamics and the water exchange. However, the hydrodyamics of the shelf zone differ considerably from those of the open expanses of seas and lakes owing to the steepness of the bottom, the complex structure of the shoreline, the major role of wind waves, and their breaking [1]. In [2, 3] the importance of surface waves and their breaking for inshore flows was demonstrated and the equations of hydrodynamics, averaged over the depth, were derived. For regions of the shelf remote from the shoreline it is also necessary to take into account the interaction of waves with the bottom and with essentially three-dimensional flows. In this note the equations of hydrodynamics are derived for wind wave flows averaged over the wave period in the threedimensional formulation.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1-, pp. 174–176, January–February, 1987. 相似文献
3.
Triple configurations of shock waves in supersonic inviscid flows of a perfect gas are considered. The basic parameters of
triple configurations are determined, and the conditions of solution existence are analyzed.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 3–10, May–June, 2008. 相似文献
4.
A. T. Il’ichev 《Fluid Dynamics》2000,35(2):157-176
The latest results relating to the theory of nonlinear waves in dispersive and dissipative media are reviewed. Attention is
concentrated on small-amplitude solitary waves and, in particular, on the classification of types of solitary waves, their
conditions of existence, the evolution of local perturbations associated with the presence of solitary waves of various types,
and problems of the existence of nonlinear waves localized with respect to a particular direction as the space dimension increases
(spontaneous dimension breaking). As examples of dispersive and dissipative media admitting plane solitary waves of various
types, we consider a cold collisionless plasma, an ideal incompressible fluid of finite depth beneath an elastic plate and
with surface tension, and a fluid in a rapidly oscillating rectangular vessel (Faraday resonance). Examples of spontaneous
dimension breaking are considered for the generalized Kadomtsev-Petviashvili equation.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 3–27. March–April, 2000.
The work was carried out with financial support from the Russian Foundation for Basic Research (project No. 99-0101150). 相似文献
5.
In recent years two nonlinear dispersive partial differential equations have attracted much attention due to their integrable
structure. We prove that both equations arise in the modeling of the propagation of shallow water waves over a flat bed. The
equations capture stronger nonlinear effects than the classical nonlinear dispersive Benjamin–Bona–Mahoney and Korteweg–de
Vries equations. In particular, they accommodate wave breaking phenomena. 相似文献
6.
B. N. Elemesova 《Journal of Applied Mechanics and Technical Physics》1999,40(1):28-35
The plane-parallel unsteady-state shear gas flow in a narrow channel of constant cross section is considered. The existence
theorem of solutions in the form of simple waves of a set of equations of motion is proved for a class of isentropic flows
with a monotone velocity profile over the channel depth. The exact solution described by incomplete beta-functions is found
for a polytropic equation of state in a class of isentropic flows.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 1, pp. 36–43, January–February, 1999. 相似文献
7.
A. K. Khe 《Journal of Applied Mechanics and Technical Physics》2009,50(2):199-206
Spatial stationary flows over an even bottom of a heavy ideal fluid with a free surface are considered. Jump relations for
flows with a strong discontinuity are studied. It is shown that the flow parameters behind the jump are defined by a certain
curve which is an analog of the (θ, p) diagram in gas dynamics. A shock polar and examples of flows with a hydraulic jump
are constructed for a particular class of solutions.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 37–45, March–April, 2009. 相似文献
8.
A new type of flow in a magnetic fluid has been experimentally detected and investigated. The interaction between an alternating
nonuniform magnetic field and a magnetic fluid leads to the parametric excitation of traveling capillary-gravitational waves
which are the direct cause of the average flow. A necessary condition of formation of hydrodynamic flows in an alternating
field is also the presence of time-dependent harmonics with multiple frequencies synchronized with the first harmonic, so
that the time dependence of the ponderomotive force is generally pulsed. It is shown that for plane vibrational flows the
classical theory cannot explain the high intensity of the average flows observed. It is suggested that the high intensity
of magnetovibrational flows is related to the violation of the cylindrical symmetry of the traveling capillary-gravitational
waves and the transition to a three-dimensional motion.
Perm’. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 124–133, January–February,
1998. 相似文献
9.
Boundary layer receptivity to two-dimensional slow and fast acoustic waves is investigated by solving Navier–Stokes equations
for Mach 4.5 flow over a flat plate with a finite-thickness leading edge. Higher order spatial and temporal schemes are employed
to obtain the solution whereby the flat-plate leading edge region is resolved by providing a sufficiently refined grid. The
results show that the instability waves are generated in the leading edge region and that the boundary-layer is much more
receptive to slow acoustic waves (by almost a factor of 20) as compared to the fast waves. Hence, this leading-edge receptivity
mechanism is expected to be more relevant in the transition process for high Mach number flows where second mode instability
is dominant. Computations are performed to investigate the effect of leading-edge thickness and it is found that bluntness
tends to stabilize the boundary layer. Furthermore, the relative significance of fast acoustic waves is enhanced in the presence
of bluntness. The effect of acoustic wave incidence angle is also studied and it is found that the receptivity of the boundary
layer on the ‘windward’ side (with respect to the acoustic forcing) decreases by more than a factor of four when the incidence
angle is increased from 0° to 45°. However, the receptivity coefficient for the ‘leeward’ side is found to vary relatively
weakly with the incidence angle.
相似文献
10.
V. M. Teshukov 《Journal of Applied Mechanics and Technical Physics》1998,39(5):699-709
The problem of the decay of an arbitrary discontinuity (the Riemann problem) for the system of equations describing vortex
plane-parallel flows of an ideal incompressible liquid with a free boundary is studied in a long-wave approximation. A class
of particular solutions that correspond to flows with piecewise-constant vorticity is considered. Under certain restrictions
on the initial data of the problem, it is proved that this class contains self-similar solutions that describe the propagation
of strong and weak discontinuities and the simple waves resulting from the nonlinear interaction of the specified vortex flows.
An algorithm for determining the type of resulting wave configurations from initial data is proposed. It extends the known
approaches of the theory of one-dimensional gas flows to the case of substantially two-dimensional flows.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 5, pp. 55–66, September–October, 1998. 相似文献
11.
A new experimental approach to the study of the two-dimensional compressible flow phenomena is presented. In this technique,
a variety of compressible flows were generated by bursting plane vertical soap films. An aureole and a “shock wave” preceding
the rim of the expanding hole were clearly observed using traditional high-speed flash photography and a fast line-scan charge
coupled device (CCD) camera. The moving shock wave images obtained from the line-scan CCD camera were similar to the x–t diagrams in gas dynamics. The moving shock waves cause thickness jumps and induce supersonic flows. Photographs of the supersonic
flows over a cylinder and a wedge are presented. The results suggest clearly the feasibility of the “soap film shock tube”.
Received: 11 May 2000/Accepted: 2 November 2000 相似文献
12.
N. V. Gavrilov E. V. Ermanyuk 《Journal of Applied Mechanics and Technical Physics》1999,40(2):258-262
Propagation of internal waves over a circular cylinder under the conditions of a continuous stratification characterized by
the presence of a high-gradient density layer (the pycnocline) of finite thickness is studied. The dependences of the coefficent
of wave propagation on the wavelength of the first-mode incident wave for various thicknesses of the pycnocline are obtained.
In the diffraction of internal waves, substantial nonlinear effects are shown to occur, which result in the appearance of
waves of double oscillation frequency compared to the frequency of the incident waves. The generation coefficient for these
waves is found.
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 2, pp. 79–85, March–April, 1999. 相似文献
13.
A. A. Chesnokov 《Journal of Applied Mechanics and Technical Physics》2000,41(4):593-603
We obtain new classes of invariant solutions of the integrodifferential equations describing the propagation of nonlinear
concentration waves in a rarefied bubbly fluid. For all the solutions obtained, trajectories of particle motion in phase space
are calculated. The stability of some flows is studied in a linear approximation. In several cases, the construction of solutions
reduces to an integrodifferential equation of the second kind, which can be solved by the iteration method.
Novosibirsk State University, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41,
No. 4, pp. 21–32, July–August, 2000. 相似文献
14.
S. I. Gorlov 《Journal of Applied Mechanics and Technical Physics》1999,40(3):393-398
A method of solving the initial boundary-value problem of the horizontal motion of a circular cylinder under the interface
between two liquids is developed within the framework of nonlinear theory and implemented numerically. Profiles of generated
waves and hydrodynamic loads are calculated for the problem of the acceleration of a circular cylinder under the free surface
of a heavy liquid. The phenomenon of wave breaking is considered in detail.
Omsk Department, Sobolev Institute of Mathematics, Siberian Division, Russian Academy of Sciences, Omsk 644099. Translated
from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 3, pp. 37–43, May–June, 1999. 相似文献
15.
E. A. Karabut 《Journal of Applied Mechanics and Technical Physics》1999,40(1):36-45
Some exact solutions of the Euler equations with a free surface in the presence of gravitation forces are found. They are
obtained by summing Witting series applied in the theory of solitary waves. It is shown that in some cases, the left-hand
half of the constructed flows is close to the left-hand half of the solitary waves.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 1, pp. 44–54, January–February, 1999. 相似文献
16.
M.S. Mughal 《Theoretical and Computational Fluid Dynamics》1998,12(4):195-217
In many fluid flows of practical importance transition is caused by the linear growth of wave instabilities, such as Tollmien–Schlichting
waves, which eventually grow to a finite size at which stage secondary instabilities come into play. If transition is to be
delayed or even avoided in such flows, then the linear growth of the disturbances must be prevented since control in the nonlinear
regime would be a considerably more difficult task. Here a strategy for active control of two-dimensional incompressible and
compressible Tollmien–Schlichting waves and its use in controlling the more practically relevant problem of crossflow instability
which arises in swept-wing flows is discussed. The control is through an active suction/blowing distribution at the wall though
the same result could be achieved by variable wall heating. In order to control the instability it is assumed that the wall
shear stress and pressure are known from measurements. It is shown that, certainly at finite Reynolds numbers, it is sufficient
to know the flow properties at a finite number of points along the wall. The cases of high and finite Reynolds numbers are
discussed using asymptotic and numerical methods respectively. It is shown that a control strategy can be developed to stop
the growth of all two-dimensional Tollmien–Schlichting waves at finite and large Reynolds numbers. Some discussion of nonlinear
effects in the presence of active control is given and the possible control of other instability mechanisms investigated.
Received 1 May 1998 and accepted 24 September 1998 相似文献
17.
Plastic strain localization is studied with the use of a high-sensitivity infrared camera. Plastic strain localization in
iron is demonstrated to be accompanied by the emergence of heat waves and their propagation over the sample surface. Constitutive
equations that describe the energy balance in the material under plastic strains are derived, and the plastic flow of iron
is analyzed. The results of research are compared with the data obtained by infrared scanning. The proposed model of strain
localization in the form of soliton-like waves (phase triggering waves) is demonstrated to agree with the kinetics of temperature
waves characterizing dissipation inherent in the development of plastic deformation.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 1, pp. 153–164, January–February, 2009. 相似文献
18.
Robert V. Wilson Pablo M. Carrica Fred Stern 《International Journal of Computational Fluid Dynamics》2013,27(2):105-125
An exploratory study of high-speed surface ship flows is performed to identify modelling and numerical issues, to test the predictive capability of an unsteady RANS method for such flows, to explain flow features observed experimentally, and to document results obtained in conjunction with the 2005 ONR Wave Breaking Workshop. Simulations are performed for a high-speed transom stern ship (R/V Athena I) at three speeds Froude number (Fr) = 0.25, 0.43 and 0.62 with the URANS code CFDSHIP-IOWA, which utilizes a single-phase level set method for free surface modelling. The two largest Fr are considered to be high-speed cases and exhibit strong breaking plunging bow waves. Structured overset grids are used for local refinement of the unsteady transom flow at medium speed and for small scale breaking bow and transom waves at high-speeds. All simulations are performed in a time accurate manner and an examination of time histories of resistance and free surface contours is used to assess the degree to which the solutions reach a steady state. The medium speed simulation shows a classical steady Kelvin wave pattern without breaking and a wetted naturally unsteady transom flow with shedding of vortices from the transom corner. At higher speeds, the solutions reach an essentially steady state and display intense bow wave breaking with repeated reconnection of the plunging breaker with the free surface, resulting in multiple free surface scars. The high-speed simulations also show a dry transom and an inboard breaking wave, followed by outboard breaking waves downstream. In comparison to an earlier dataset, resistance is well predicted over the three speeds. The free surface predictions are compared with recent measurements at the two lowest speeds and show good agreement for both non-breaking and breaking waves. 相似文献
19.
V. P. Reutov G. V. Rybushkina 《Journal of Applied Mechanics and Technical Physics》2000,41(4):637-646
Nonlinear evolution of hydroelastic instability arising in the flow past a coating of a rubber-type material by a turbulent
boundary layer of an incompressible fluid is studied. A nonlinear dispersion equation for two-dimensional, quasi-monochromatic,
low-amplitude waves is derived. The Prandtl equations for the mean (over the waviness period) boundary-layer flow are solved
in the approximation of local similarity and by direct numerical integration. Evolution of unstable waves in time is studied
on the basis of the Landau equation, which is derived separately for the instability of fast waves (flutter) and the quasi-static
instability (divergence). The calculation results are compared with available experimental data.
Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod 603600. Translated from Prikladnaya Mekhanika
i Tekhnicheskaya Fizika, Vol. 41, No. 4, pp. 69–80, July–August, 2000. 相似文献
20.
François Golanski Véronique Fortuné Eric Lamballais 《Theoretical and Computational Fluid Dynamics》2005,19(6):391-416
The ability of Lighthill's analogy to predict the sound radiated by a transitional mixing layer is evaluated by means of direct
numerical simulation (DNS). The specific case of low Mach number flows with density variations is investigated. In order to
limit the global computational cost, the acoustic source information is based on numerical results where the sound waves have
been removed. It is shown that the low Mach number approximation coupled with the acoustic analogy can lead to very accurate
predictions for the radiated sound if the acoustic sources in Lighthill's equation are taken into account carefully. Results
for the acoustic intensity deduced from a repeated use of the Lighthill's analogy over a wide range of Mach numbers allow
us to discuss the adequacy of scaling laws proposed by previous authors (J. Sound Vib. 28(3), 563–585, 1973; 31(4), 391–397, 1973; 48(1), 95–111, 1976) for the prediction of noise from hot jets. 相似文献