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Wyszukujesz frazę "slip boundary conditions" wg kryterium: Wszystkie pola


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Tytuł:
Experimental Determination of Limit Adhesive Shear Stress between Solid Wall and Liquid
Autorzy:
Sawicki, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/241430.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
hydromechanics
slip boundary conditions
adhesion
Opis:
The slip boundary condition can be a very useful relation when some specific problems of hydromechanics are considered. According to the classical form of this condition, the slip of a fluid with respect to the solid wall should occur even at a very low velocity of motion. However, both theoretical analysis and certain empirical data suggest that there must be a limit value of the wall shear stress, below which the slip does not occur. According to the simplified balance of adhesive and gravitational forces, a simple experimental method for determining this stress has been proposed and applied in this paper.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 175--181
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Motion of a particle with stick-slip boundary conditions towards a flat interface: hard wall or free surface
Autorzy:
Ekiel-Jeżewska, M.
Wajnryb, E.
Powiązania:
https://bibliotekanauki.pl/articles/109616.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle
boundary conditions
hard wall
free surface
Opis:
Motion of a particle with stick-slip boundary conditions towards a hard wall or free surface is investigated in the range of Reynolds numbers much smaller than unity, based on the multipole expansion of the Stokes equations. The slip parameter can be interpreted as a measure of a solid particle roughness or as the effect of a surfactant on the motion of a small spherical non-deformable bubble. The particle friction coefficient is evaluated as a function of the distance from its center to the wall, based on the inverse power series expansion, and the results are used to derive explicit lubrication expressions for the friction coefficient, in a wide range of the slip parameters. It is pointed out that for a very small thickness of the fluid film, the lubrication expressions are more accurate than the series expansion. The drainage time is calculated and analyzed, and estimated in terms of explicit lubrication expressions.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 203-209
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds
Autorzy:
Jóźwik, P.
Karcz, M.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/185029.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CFD
mikroreaktor
modelowanie
microreactor
modelling
slip boundary conditions
Opis:
In this paper a three-dimensional model for determination of a microreactor's length is presented and discussed. The reaction of thermocatalytic decomposition has been implemented on the base of experimental data. Simplified Reynolds-Maxwell formula for the slip velocity boundary condition has been analysed and validated. The influence of the Knudsen diffusion on the microreactor's performance has also been verified. It was revealed that with a given operating conditions and a given geometry of the microreactor, there is no need for application of slip boundary conditions and the Knudsen diffusion in further analysis. It has also been shown that the microreactor's length could be practically estimated using standard models.
Źródło:
Chemical and Process Engineering; 2011, 32, 3; 215-227
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical solutions of a steady 2-D incompressible flow in a rectangular domain with wall slip boundary conditions using the finite volume method
Autorzy:
Ambethkar, V.
Srivastava, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/973635.pdf
Data publikacji:
2017
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
finite volume method
numerical solutions
pressure
Reynolds number
SIMPLE algorithm
staggered grid
u-velocity
v-velocity
przepływy cieczy
metoda objętości skończonej
metody numeryczne
liczba Reynoldsa
algorytm SIMPLE
metoda siatek przesuniętych
Opis:
In this study, a finite volume method (FVM) is suitably used for solving the problem of a fully coupled fluid flow in a rectangular domain with slip boundary conditions. Numerical solutions for the flow variables, viz. velocity, and pressure have been computed. The FVM, with an upwind scheme, has been implemented to discretize the governing equations of the present problem. The well known SIMPLE algorithm is employed for pressure-velocity coupling. This was executed with the aid of a computer program developed and run in a C-compiler. Computations have been performed for unknown variables with Reynolds numbers (Re) = 50, 100, 250, 500, 750 and 1000. The behavior of steady-state solutions of velocity and pressure of the fluid along horizontal and vertical through geometric center of the rectangular domain have been illustrated. We observed that, with the increase of the Reynolds number, the absolute value of velocity components decreases whereas the pressure value increases.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2017, 16, 2; 5-16
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of MHD fluid with second order slip and thermal flow over a nonlinear stretching sheet
Autorzy:
Jauhri, Shefali
Mishra, Upendra
Powiązania:
https://bibliotekanauki.pl/articles/2174199.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
płyn magnetyczny
nanociecz
metoda Runge-Kutty
stagnation point flow
second order slip boundary conditions
nonlinear stretching sheet
Runge-Kutta method
Opis:
An electrically conducted viscous incompressible nanofluid flow caused by the nonlinear stretching surface with stagnation flow has been investigated numerically. The effect of Brownian motion and thermophoresis on the nanofluid is also incorporated. The governing partial differential equations with nonlinear second order boundary conditions are solved by the fourth order Runge-Kutta technique using MATLAB programming. The effect of the radiation parameter (Rd), stretching parameter (n), Brownian motion parameter (Nb), thermophoresis parameter (Nt) on temperature, velocity and mass transfer are shown graphically. The influence of some of these parameters on the local Nusselt number (−′(0)) and local Sherwood number (−′(0)) are shown by the graphs.
Źródło:
International Journal of Applied Mechanics and Engineering; 2022, 27, 2; 98--114
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined effects of Soret and Dufour on MHD flow of a power-law fluid over flat plate in slip flow rigime
Autorzy:
Saritha, K.
Rajasekhar, M. N.
Reddy, B. S.
Powiązania:
https://bibliotekanauki.pl/articles/265391.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
liczba Prandtla
warunki granicy poślizgu
zjawisko Dufoura
power-law fluid
Soret and Dufour number
slip boundary conditions
finite difference method
Prandtl number
Opis:
A numerical model is developed to study the Soret and Dufour effects on MHD boundary layer flow of a power-law fluid over a flat plate with velocity, thermal and solutal slip boundary conditions. The governing equations for momentum, energy and mass are transformed to a set of non-linear coupled ordinary differential equations by using similarity transformations. These non-linear ordinary differential equations are first linearized using a quasi-linearization technique and then solved numerically based on the implicit finite difference scheme over the entire range of physical parameters with appropriate boundary conditions. The influence of various governing parameters along with velocity, thermal and mass slip parameters on velocity, temperature and concentration fields are examined graphically. Also, the effects of slip parameters, the Soret and Dufour number on the skin friction, Nusselt number and Sherwood number are studied. Results show that the increase in the Soret number leads to a decrease in the temperature distribution and to an increase in concentration fields.
Źródło:
International Journal of Applied Mechanics and Engineering; 2018, 23, 3; 689-705
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Foundations of the Navier-Stokes boundary conditions in fluid mechanics
Autorzy:
Badur, J.
Karcz, M.
Lemański, M.
Nastałek, L.
Powiązania:
https://bibliotekanauki.pl/articles/175407.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
enhancement
slip
Navier number
Navier-Stokes
nanoflow
Opis:
Until recently it was believed that Navier’s boundary condition could be given as a rigorous foundation for slip phenomena. Due to the latest measurements in the mass flow rate of a gas flowing through nano- and microchannels, several discrepancies in the mathematical modelling have been found. Thus, in the literature, the opinion persists for the Navier slip condition to be correct only under certain circumstances, particularly those restricted to the first order boundary conditions. One of many ways to eliminate this discrepancy, which is extensively employed in the contemporary literature, is to develop a variety of the so-called second order boundary conditions. This path, however, seems incorrect since it lacks consistency between the bulk stress tensor and its boundary representation. In the paper we propose to replace the classical Navier slip condition with the new, more general Navier-Stokes slip boundary condition. Instead of the usual method of consideration, the boundary condition is presented as following from the mass and momentum balances within a thin, shell-like moving layer. Owing to this, the problem of consistency between the internal and external friction in a viscous fluid is solved within the framework of new layer balances, and a proper form of constitutive relations for friction and mobility forces. Finally, the common features of the Navier, Stokes, Maxwell and Reynolds concepts of a boundary slip layer are compared and revalorized. The classifications of different mobility mechanisms, important for flows in nano-, microchannels are also discussed.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2011, 123; 3-55
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An overview of heat transfer enhancement based upon nanoparticles influenced by induced magnetic field with slip condition via finite element strategy
Autorzy:
Hafeez, Muhammad B.
Krawczuk, Marek
Shahzad, Hasan
Powiązania:
https://bibliotekanauki.pl/articles/2105987.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
magnetohydrodynamic flow
porous medium
nanofluids
heat transfer
thermal performance
convective boundary conditions
FEM
Opis:
The mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively to explore the phenomenon of thermal performance of the combination fluid. A remarkable enhancement in thermal performance is noticed when solid structures are dispersed in the working fluid. The Biot number determines the convective nature of the boundary. When the Biot number is increased, the fluid temperature decreases significantly. Among copper oxide, aluminium oxide, and titanium oxide nanoparticles, copper oxide nanoparticles are found to be the most effective thermal enhancers.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 3; 200--206
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Investigation of Interfacial Conditions between Fluid and Porous Layer Formed by Periodic Arrays of Circular and Non-Circular Cylinders
Autorzy:
Cihat Baytaş, A.
Erdem, D.
Acar, H.
Cetiner, O.
Başcı, H.
Powiązania:
https://bibliotekanauki.pl/articles/1030800.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
flows through porous media
interfacial flows
interface slip coefficient
interface geometry
composite channel
PIV
boundary condition
Opis:
In this experimental study, a flow through a two-dimensional channel partially containing porous media is investigated. A two-layer structure comprising of a saturated porous layer with an overlaying fluid flow layer in a rectangular horizontal channel is designed for the experiments. Flow characteristics at the interface between clear fluid and porous layer are investigated. The porous layer consists of cylindrical rod bundle placed horizontally on the side walls of the channel in arranged square arrays. In the experiments, water white oil is used as the working fluid to match the refractive index of the cylindrical rods made of Plexiglas. Visualizations and measurements have been acquired by digital particle image velocimetry system for the velocity profiles which help us to evaluate the interface velocity and slip coefficient at the interface region. The measurement of interface velocity profile is repeated for circular, square, and 45^{°} rotated square cylindrical rods to understand the effects of the structure of the interface region. It has been observed that dimensionless slip or interface velocity depends significantly on the surface structure at the interface region when cylindrical rods each with circular, square, and 45^{°} rotated square cross-sections are used as porous medium. The volumetric flow rate can be changed according to the cross-sections of cylindrical rods. The permeability for the different arrangements of cylindrical rods is computed by an analytical study. The dimensionless slip velocity, slip coefficient, particle image velocimetry images, experimental and numerical velocity vector maps, and velocity profiles at the interface are presented.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1314-1323
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of heat generation/absorption on mixed convection flow behaviour in the presence of Lorentz forces in a vertical micro circular duct having time periodic boundary conditions: steady periodic regime
Autorzy:
Aina, B.
Isa, S.
Powiązania:
https://bibliotekanauki.pl/articles/1839783.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
konwekcja mieszana
mikrokanał
wytwarzanie ciepła
poślizg
mixed convection
micro circular duct
Lorentz force
heat generation
heat absorption
slip and jump
time
Opis:
The problem of mixed convection flow of a heat generating/absorbing fluid in the presence existence of Lorentz forces in a vertical micro circular subjected to a periodic sinusoidal temperature change at the surface has been studied taking the first-order slip and jump effects into consideration. The research analysis is carried out by considering a fully developed parallel flow and steady periodic regime. The governing equations, together with the constraint equations which arise from the definition of mean velocity and temperature, are written in a dimensionless form and mapped into equations in the complex domain. One obtains two independent boundary value problems, which provide the mean value and the oscillating term of the velocity and temperature distributions. These boundary value problems are solved analytically. A parametric study of some of the physical parameters involved in the problem is conducted. The results of this research revealed that the magnetic field has a damping impact on the flow and results in decreases in fluid velocity for both air and water. Furthermore, the presence of the heat generation parameter is seen to enhance the temperature distribution and this is reflected as an increase in the magnitude of the oscillation dimensionless velocity, whereas in the presence of heat absorption a reversed trend occurs.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 4; 1-21
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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