A pulsating laminar flow of a viscous, incompressible liquid in a rectangul
ar duct has been studied. The motion is induced under an imposed pulsating
pressure difference. The problem is solved numerically. Different flow regi
mes are characterized by a non-dimensional parameter based on the frequency
(omega) of the imposed pressure gradient oscillations and the width of the
duct (h). This, in fact, is the Reynolds number of the problem at hand. Th
e induced velocity has a phase lag (shift) with respect to the imposed pres
sure oscillations, which varies from zero at very slow oscillations, to 90
degrees at fast oscillations. The influence of the aspect ratio of the rect
angular duct and the pulsating pressure gradient frequency on the phase lag
, the amplitude of the induced oscillating velocity, and the wall shear wer
e analyzed. Copyright (C) 1999 John Wiley & Sons, Ltd.