Boundary-layer separation at a free streamline Part 2. Numerical results

1971 ◽  
Vol 46 (4) ◽  
pp. 727-736 ◽  
Author(s):  
R. C. Ackerberg
Keyword(s):  
Boundary Layer ◽  
Asymptotic Expansion ◽  
Asymptotic Solution ◽  
Numerical Solution ◽  
Boundary Layer Flow ◽  
Boundary Layer Separation ◽  
Multiplicative Constant ◽  
Boundary Layer Equations ◽  
Layer Flow ◽  
Uniform Stream

An asymptotic solution of the boundary-layer equations, valid just upstream of a free streamline attached to the sharp trailing edge of a body, is compared with a numerical solution for the boundary-layer flow on a finite flat plate set perpendicular to a uniform stream. An arbitrary multiplicative constant in the asymptotic expansion, arising from an eigenfunction, is evaluated by requiring the skin friction to agree with a numerical value close to the free streamline. Using this value, the velocity profiles, computed from the asymptotic expansion, are in excellent agreement with the numerical solution.

scholarly journals Magnetohydrodynamic cross-field boundary layer flow

1982 ◽  
Vol 5 (2) ◽  
pp. 377-384 ◽  
Author(s):  
D. B. Ingham ◽  
L. T. Hildyard
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Asymptotic Solution ◽  
Boundary Layer Flow ◽  
Leading Edge ◽  
Field Boundary ◽  
Boundary Layer Equations ◽  
Mhd Boundary Layer ◽  
Blasius Boundary Layer ◽  
Layer Flow

The Blasius boundary layer on a flat plate in the presence of a constant ambient magnetic field is examined. A numerical integration of the MHD boundary layer equations from the leading edge is presented showing how the asymptotic solution described by Sears is approached.

Three-Dimensional Boundary-Layer Flow About an Ablating Slender Cone

1969 ◽  
Vol 91 (4) ◽  
pp. 632-648 ◽  
Author(s):  
T. K. Fannelop ◽  
P. C. Smith
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Cone Angle ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Boundary Layer Equations ◽  
Transverse Curvature ◽  
Dimensional Boundary ◽  
Layer Flow

A theoretical analysis is presented for three-dimensional laminar boundary-layer flow about slender conical vehicles including the effect of transverse surface curvature. The boundary-layer equations are solved by standard finite difference techniques. Numerical results are presented for hypersonic flow about a slender blunted cone. The influences of Reynolds number, cone angle, and mass transfer are studied for both symmetric flight and at angle-of-attack. The effects of transverse curvature are substantial at the low Reynolds numbers considered and are enhanced by blowing. The crossflow wall shear is largely unaffected by transverse curvature although the peak velocity is reduced. A simplified “channel flow” analogy is suggested for the crossflow near the wall.

Flow Characteristics around Circular Cylinders with a Normal Slit

2017 ◽  
Vol 379 ◽  
pp. 48-57 ◽  
Author(s):  
Cheng Hsiung Kuo ◽  
Hwa Wei Lin ◽  
Chih Tao Chai ◽  
Fred Cheng
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Boundary Layer Flow ◽  
Rear Surface ◽  
Flow Characteristics ◽  
Boundary Layer Separation ◽  
Circular Cylinders ◽  
Flow Structures ◽  
Phase Lock ◽  
Layer Flow

Alterations of boundary layer separation along the upper-rear surface of a baseline and slit cylinder and the formation of a vortex in the near-wake are investigated by particle image velocimetry (PIV) at Reynolds number 1000. The slit ratio (S/D) is 0.3. The phase-lock flow structures are referred to the time-dependent volume flux at the slit exit and are achieved by the modified phase-averaged technique. The alterations and the evolution of boundary-layer flow along the upper-rear surface are demonstrated by the phase-lock flow structures. It is found that the alternate blowing and suction at the slit exit serves as a perturbation to the boundary layer near the shoulder of the slit cylinder leading to a significant delay of flow separation and the flow reattachment of boundary-layer flow along the upper-rear surface of the cylinder. After perturbation, the vortex street behind a slit cylinder is more organized and stronger than that behind a baseline cylinder at Reynolds number 1000.

Numerical Solution of Laminar Boundary Layer Flow About a Rotating Sphere in an Axial Stream

1985 ◽  
Vol 107 (1) ◽  
pp. 97-104 ◽  
Author(s):  
M. A. I. El-Shaarawi ◽  
M. F. El-Refaie ◽  
S. A. El-Bedeawi
Keyword(s):  
Boundary Layer ◽  
Present Scheme ◽  
Rotating Sphere ◽  
Boundary Layer Equations ◽  
Meridional Velocity ◽  
Axis Of Rotation ◽  
Stress Components ◽  
Layer Flow ◽  
Momentum Integral ◽  
Uniform Stream

A finite-difference scheme is developed for solving the boundary layer equations governing the laminar flow about a rotating sphere which is subjected to a uniform stream in the direction of the axis of rotation. Numerical results are presented for the meridional and azimuthal velocities and for the wall-shear-stress components. Also, the angle at which the meridional velocity gradient normal to the wall vanishes is given at values of the parameter Ta/Re2 ranged from zero (the stationary sphere case) to 10000. As compared with the momentum integral technique of Schlichting [8], the present scheme succeeded in obtaining solutions for very considerably larger values of the parameter Ta/Re2.

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