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Civil-Comp Proceedings
ISSN 1759-3433 CCP: 76
PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE ON ENGINEERING COMPUTATIONAL TECHNOLOGY Edited by: B.H.V. Topping and Z. Bittnar
Paper 26
Numerical Simulation of the Flow Induced by a Circular Cylinder Subject to Forced Oscillations S. Kocabiyik+ and F.M. Mahfouz*
+Department of Mathematics and Statistics, Memorial University, St. John's, Newfoundland, Canada
Full Bibliographic Reference for this paper
S. Kocabiyik, F.M. Mahfouz, "Numerical Simulation of the Flow Induced by a Circular Cylinder Subject to Forced Oscillations", in B.H.V. Topping, Z. Bittnar, (Editors), "Proceedings of the Third International Conference on Engineering Computational Technology", Civil-Comp Press, Stirlingshire, UK, Paper 26, 2002. doi:10.4203/ccp.76.26
Keywords: numerical simulation, unsteady, incompressible, viscous, rectilinear oscillations, cylinder.
Summary
The problem of unsteady, laminar flow past a circular cylinder
which performs recti-linear oscillations at an arbitrary angle
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From the standpoint of controlling laminar two-dimensional vortex
shedding from a circular cylinder by using "active control" of
the nature of the vortex shedding process can be significantly
altered by cylinder oscillation. Generally speaking, the control
of flow physics and near-wake structure of a bluff body may take
the form of global control, where the entire body is subjected to
prescribed motion, or local control, involving localized
application of unsteady blowing/suction or heating at specified
positions on the surface of the stationary body. Attention here is
focused on the case of global control where the time-dependent
dimensionless recti-linear oscillatory velocity of a circular
cylinder is represented by
For a cylinder, placed in a uniform free-stream, subject to recti-linear
oscillations the flow field depends mainly on three dimensionless
parameters. The first is the Reynolds number, defined as The investigation is based on the solution of unsteady Navier-Stokes equations together with the mass conservation equation in the case of viscous fluids. The method of solution is based on the use of truncated Fourier series representations for the stream function and vorticity in the angular polar coordinate. A non-inertial coordinate transformation is used so that the grid mesh remains fixed relative to the accelerating cylinder. The Navier-Stokes equations are reduced to ordinary differential equations in the spatial variable and these sets of equations are solved by using finite difference methods, but with the boundary vorticity calculated using integral conditions rather than local finite-difference approximations.
The cylinder motion starts suddenly from rest at time
The numerical method is verified for small times by comparison
with the analytical results of a perturbation series solution and
an excellent agreement is found. The time variation of the in-line
and transverse force coefficients are first presented for three
values of the forced frequency purchase the full-text of this paper (price £20)
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