Higher-order boundary-layer solution for unsteady motion of a circular cylinder

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6418172

Nam, S

The higher-order boundary-layer solution for an impulsively moving circular cylinder with uniform velocity and an exponentially accelerating cylinder in incompressible, relatively high-Reynolds-number flow of short duration is considered. A perturbation method is employed to linearize the two-dimensional vorticity equation by a double-series expansion with respect to the Reynolds number and the time. A matched asymptotic expansion is carried out to define the proper boundary conditions between the viscous and inviscid layers for the linearized first-, second-, and third-order boundary-layer equations. Singularities appear in the viscous displacement velocities and skin frictions in the higher-order approximate solutions that coincide with the singularity of the first-order approximate solution. These singularities have alternating signs and increasing magnitudes so an attempt was made to remove the effects of the singularity of the lower-order solution. However this attempt at removing a singularity by superposing even stronger singularities makes the solution worse around the singularity, and the boundary-layer assumptions break down at that point.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6418172
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ANALYTICAL SOLUTION
ASYMPTOTIC SOLUTIONS
BOUNDARY LAYERS
CYLINDERS
FLUID FLOW
INCOMPRESSIBLE FLOW
LAYERS
REYNOLDS NUMBER
UNSTEADY FLOW
VISCOUS FLOW