Author:
GRAHAM D. R.,HIGDON J. J. L.
Abstract
Numerical computations are employed to study the phenomenon of oscillatory forcing
of flow through porous media. The Galerkin finite element method is used to solve the
time-dependent Navier–Stokes equations to determine the unsteady velocity field and
the mean flow rate subject to the combined action of a mean pressure gradient and
an oscillatory body force. With strong forcing in the form of sinusoidal oscillations,
the mean flow rate may be reduced to 40% of its unforced steady-state value. The
effectiveness of the oscillatory forcing is a strong function of the dimensionless forcing
level, which is inversely proportional to the square of the fluid viscosity. For a porous
medium occupied by two fluids with disparate viscosities, oscillatory forcing may be
used to reduce the flow rate of the less viscous fluid, with negligible effect on the
more viscous fluid. The temporal waveform of the oscillatory forcing function has a
significant impact on the effectiveness of this technique. A spike/plateau waveform is
found to be much more efficient than a simple sinusoidal profile. With strong forcing,
the spike waveform can induce a mean axial flow in the absence of a mean pressure
gradient. In the presence of a mean pressure gradient, the spike waveform may be
employed to reverse the direction of flow and drive a fluid against the direction of
the mean pressure gradient. Owing to the viscosity dependence of the dimensionless
forcing level, this mechanism may be employed as an oscillatory filter to separate
two fluids of different viscosities, driving them in opposite directions in the porous
medium. Possible applications of these mechanisms in enhanced oil recovery processes
are discussed.
Publisher
Cambridge University Press (CUP)
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics
Cited by
15 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献