On a New Approach to Slip Flow Using Rayleigh’s Problem

1967 ◽  
Vol 34 (4) ◽  
pp. 837-839 ◽  
Author(s):  
E. P. Russo ◽  
O. A. Arnas

A new approach, involving a perturbation of the Navier-Stokes equations, is used to analyze the phenomenon of slip flow over a flat plate. An expression for the coefficient of drag is derived and compared to the drag coefficient obtained by the traditional approach of solving the Navier-Stokes equations with a slip-velocity boundary condition.

1965 ◽  
Vol 22 (3) ◽  
pp. 463-469 ◽  
Author(s):  
J. D. Murray

An asymptotic solution to the Navier-Stokes equation is obtained for the incompressible flow of a viscous fluid past a semi-infinite flat plate when a slip boundary condition is applied at the plate. The results for the shear stress (and hence the slip velocity) on the plate differ basically from those obtained by previous authors who considered the same problem using some form of the Oseen equations.


Author(s):  
Joris C. G. Verschaeve

By means of the continuity equation of the incompressible Navier–Stokes equations, additional physical arguments for the derivation of a formulation of the no-slip boundary condition for the lattice Boltzmann method for straight walls at rest are obtained. This leads to a boundary condition that is second-order accurate with respect to the grid spacing and conserves mass. In addition, the boundary condition is stable for relaxation frequencies close to two.


It is shown that the boundary layer approximation to the flow of a viscous fluid past a flat plate of length l , generally valid near the plate when the Reynolds number Re is large, fails within a distance O( lRe -3/4 ) of the trailing edge. The appropriate governing equations in this neighbourhood are the full Navier- Stokes equations. On the basis of Imai (1966) these equations are linearized with respect to a uniform shear and are then completely solved by means of a Wiener-Hopf integral equation. The solution so obtained joins smoothly on to that of the boundary layer for a flat plate upstream of the trailing edge and for a wake downstream of the trailing edge. The contribution to the drag coefficient is found to be O ( Re -3/4 ) and the multiplicative constant is explicitly worked out for the linearized equations.


Author(s):  
Arash Karimipour ◽  
Masoud Afrand

Forced convection of water–Cu nanofluid in a two-dimensional microchannel is studied numerically. The microchannel wall is divided into three parts. The entry and exit ones are kept insulated while the middle one has more temperature than the inlet fluid. The whole of microchannel is under the influence of a magnetic field with uniform strength of B0. Slip velocity and temperature jump are involved along the microchannel walls for different values of slip coefficient such as B = 0.001, B = 0.01, and B = 0.1 for Re = 10, Re = 50, and Re = 100. Navier–Stokes equations are discretized and numerically solved by a developed computer code in FORTRAN. Results are presented as the velocity, temperature, and Nusselt number profiles. Moreover, the effect of magnetic field on slip velocity and temperature jump is investigated for the first time in the present work. Larger Hartmann number, Reynolds number, and volume fraction correspond to more heat transfer rate; however, the effects of Ha and ϕ are more significant at higher Re.


1993 ◽  
Vol 115 (1) ◽  
pp. 110-117 ◽  
Author(s):  
M. Giles ◽  
R. Haimes

This paper describes and validates a numerical method for the calculation of unsteady inviscid and viscous flows. A companion paper compares experimental measurements of unsteady heat transfer on a transonic rotor with the corresponding computational results. The mathematical model is the Reynolds-averaged unsteady Navier–Stokes equations for a compressible ideal gas. Quasi-three-dimensionality is included through the use of a variable streamtube thickness. The numerical algorithm is unusual in two respects: (a) For reasons of efficiency and flexibility, it uses a hybrid Navier–Stokes/Euler method, and (b) to allow for the computation of stator/rotor combinations with arbitrary pitch ratio, a novel space–time coordinate transformation is used. Several test cases are presented to validate the performance of the computer program, UNSFLO. These include: (a) unsteady, inviscid flat plate cascade flows (b) steady and unsteady, viscous flat plate cascade flows, (c) steady turbine heat transfer and loss prediction. In the first two sets of cases comparisons are made with theory, and in the third the comparison is with experimental data.


2010 ◽  
Vol 24 (13) ◽  
pp. 1333-1336
Author(s):  
LIN CHEN ◽  
DENGBIN TANG ◽  
XIN GUO

The convection and diffusion processes of free vortex in compressible flows are simulated by using high precision numerical method to solve for the Navier–Stokes equations. Accurate treatment of the boundary condition is extremely important for simulation of vortex flows. The developed numerical methods are well presented by combining six-order non-dissipation compact schemes with Navier–Stokes characteristic boundary condition having transverse and viscous terms, and can accurately simulate the movement of free vortex. The numerical reflecting waves at the boundaries are well controlled.


1967 ◽  
Vol 27 (4) ◽  
pp. 691-704 ◽  
Author(s):  
R. T. Davis

Laminar incompressible flow past a semi-infinite flat plate is examined by using the method of series truncation (or local similarity) on the full Navier-Stokes equations. The first and second truncations are calculated at points on the plate away from the leading edge, while only the first truncation is calculated at the leading edge. The solutions are compared with the results from other approximate methods.


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