M. O. Levi, G. Yu. Levi, V. A. Lyzhov
Southern Scientific Center, Russian Academy of Sciences, Rostov-on-Don, 344006, Russia
Keywords: электромагнитоупругость, сегнетоэлектрики, ферромагнетики, функция Грина, слоистые структуры, фазовые скорости, electromagnetoelastic, ferroelectrics, ferromagnets, Green's function, layered structures, phase velocities
This paper considers the dynamic coupled problem of harmonic oscillations of a layered inhomogeneous electromagnetoelastic medium subjected to an oscillating mechanical or electrical load under various electric and magnetic field conditions specified on the surface and internal boundaries of this medium. Green's function for the medium is constructed. Dispersion curves and phase velocities for different boundary conditions and materials are obtained.
S. Ijaz1, N. Saleem2, S. Munawar1,3 1School of Science and Technology, Lahore, 54000, Pakistan 2College of Business Administration, Dammam, Saudi Arabia 3Prince Mohammad Bin Fahd University, Al Khobar, 31952, Saudi Arabia
Keywords: поперечный массообмен, аналитическое решение, течение в канале, магнитогидродинамика, условия скольжения, across mass transfer (AMT), analytical solution, channel flow, MHD, slip condition
T. Hayat1,2, F. M. Abbasi3, A. Alsaedi2 1Quaid-I-Azam University, Islamabad, 44000, Pakistan 2Nonlinear Analysis and Applied Mathematics Research Group, Jeddah, 21589, Saudi Arabia 3COMSATS Institute of Information Technology, Islamabad, 44000, Pakistan
Keywords: перистальтическое движение, джоулев нагрев, эффекты Соре и Дюфура, peristaltic transport, Joule heating, Soret and Dufour effects
Simultaneous effects of heat and mass transfer in peristaltic transport of a viscous fluid are considered. Mathematical modeling is provided in the presence of the Joule heating and the Soret and Dufour effects. The analysis is performed using the long wavelength and low Reynolds number considerations. Perturbation solutions are obtained for a small Brinkman number.
R. Kandasamy1, V. V. Balachandar2, S. B. Hasan2 1Research Centre for Computational Mathematics, Malaysia 2Universiti Tun Hussein Onn, Johor, Malaysia
Keywords: поток вблизи точки торможения, наножидкость, броуновское движение, термофорез, магнитное поле, stagnation-point flow, nanofluid, Brownian motion, thermophoresis, magnetic field
A steady two-dimensional magnetohydrodynamic stagnation-point flow of an electrically conducting fluid and heat transfer with thermal radiation of a nanofluid past a shrinking and stretching sheet is investigated numerically. The model used for the nanofluid incorporates the effects of the Brownian motion and thermophoresis. A similarity transformation is used to convert the governing nonlinear boundary-layer equations into coupled higher-order nonlinear ordinary differential equations. The result shows that the velocity, temperature, and concentration profiles are significantly influenced by the Brownian motion, heat radiation, and thermophoresis particle deposition
I. V. Sturova
a:2:{s:4:"TYPE";s:4:"TEXT";s:4:"TEXT";s:112:"Lavrent’ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia";}
Keywords: линейная теория мелкой воды, изгибно-гравитационные волны, вязкоупругий ледяной покров, вертикальная стенка, периодическая внешняя нагрузка, краевые волны, linear shallow water theory, bending gravity waves, viscoelastic ice cover, vertical wall, periodic external load, edge waves
This paper presents the solution of the linear hydroelastic problem of stabilized forced vibrations of a semi-infinite ice cover under the effect of localized external load. The ice cover is simulated by a viscoelastic thin plate, the thickness of the liquid layer is assumed to be small, and the shallow water theory is used. The liquid is limited by a solid vertical wall, and the straight edge of the elastic plate adjacent to the wall can be both free and clamped. The solution is obtained with the help of the Fourier integral transform. The behavior of the ice cover is studied in terms of the frequency of the external load and boundary conditions on the edge of the plate. It is shown that, in the case of a free edge of the plate, there are considerable bends on the edge, which could be comparable with bends at the center of the pressure impact region. It is established that, due to the existence of wave movements of the type of edge waves, the external load energy is transferred to larger distances along the free edge, and there are significant bending moments on the edge of the clamped plate, which can lead to fracture of the ice cover at sufficiently great intensity of the external load.
M. V. Norkin
Institute of Mathematics, Mechanics and Computer Science, Rostov-on-Don, 344090, Russia
Keywords: идеальная несжимаемая жидкость, круговой цилиндр, удар, кавитационное торможение, свободная граница, каверна, малые времена, число Фруда, ideal incompressible fluid, circular cylinder, impact, cavitation deceleration, free boundary, cavity, small times, Froude number
The formation of a cavity during vertical impact and subsequent deceleration of a circular cylinder semi-submerged in a liquid is investigated. The problem with unilateral constraints is formulated to determine the initial regions of separation and contact of liquid particles and the perturbation of the internal and external free boundaries of the liquid at small times. The problem is solved using a direct asymptotic method which is effective at small times. Examples of numerical calculations of the formation of one or two cavities near the boundary of the body are given. It is shown that the acceleration of the cylinder has a significant impact on the liquid flow pattern near the body at small times.
L. A. Tolokonnikov, N. V. Larin
Tula State University, Tula, 300012, Russia
Keywords: отражение и прохождение звука, неоднородный термоупругий слой, теплопроводная жидкость, reflection and transmission of sound, inhomogeneous thermoelastic layer, heat-conducting liquid
An analytical solution of the problem of the passage of a plane sound wave through a discretely inhomogeneous thermoelastic layer adjacent to inviscid heat-conducting liquids. Results of calculations of the dependences of the transmission coefficient on the wave incidence angle and frequency for discretely inhomogeneous and continuously inhomogeneous thermoelastic layers are given. It is shown that a thermoelastic layer with continuously inhomogeneous thickness can be simulated using a system of homogeneous thermoelastic layers.
H. Babaei, T. Mirzababaie Mostofi, M. Alitavoli, A. Saeidinejad
University of Guilan, Rasht, 3756-41635, Iran
Keywords: деформирование, прямоугольная пластина, гидродинамика, ударник, ударная волна, deformation, rectangular plate, hydrodynamics, drop hammer, shock wave
This paper describes an experimental setup consisting of a drop hammer and a shock tube filled with a liquid, where a shock wave is formed, and results of experiments performed with fully clamped rectangular plates subjected to an impact load of the water shock wave. The results are presented in terms of the central deflection of the plates as a function of the kinetic energy of the drop hammer. The singular value decomposition method is used in conjunction with dimensionless numbers to obtain analytical dependences of the central deflection of the plates on the impact load parameters.
B. A. Mustafayev
Institute of Mathematics and Mechanics, Azerbaijan National Academy of Sciences, Baku, AZ1141, Azerbaijan
Keywords: щель переменной ширины, неоднородное поле напряжений, температурное поле, контактные напряжения, сцепление, проскальзывание, slit of variable width, inhomogeneous stress field, temperature field, contact stresses, adhesion, slippage
This paper touches upon changes in the temperature field near the ends of a slit of variable width under the action of an inhomogeneous stress field. The solution of the boundary-value problem on the equilibrium of the slit with partially contacting edges (there is adhesion of the edges on a certain part of the contact zone and slippage on another one) under the action of the outer inhomogeneous stress field, temperature field, and efforts on the contacting surfaces of the slit of variable width comparable with displacements in an elastic state is reduced to the problem of linear conjugation of analytic functions.
E. P. Fel'dman1, N. A. Kalugina1, T. N. Meln'ik2 1Institute for Physics of Mining Processes, National Academy of Sciences Ukraine, Dnepropetrovsk, 49600, Ukraine 2Galkin Donetsk Physical-Technical Institute, Donetsk, 83114, Ukraine
Keywords: угольный пласт, газонаполненная трещина, фильтрация, диффузия, выброс, coal bed, gas-filled crack, filtration, diffusion, emission
The development of main cracks in a coal bed due to rapid unloading is analyzed using the methods of theoretical physics. A fracture criterion and a criterion for the time to fracture of a site on the edge of the bed are obtained.