Inertia and streamline curvature effects on peristaltic pumping

Abstract Peristaltic pumping by an infinite train of sinusoidal waves in the walls of a two-dimensional tube is investigated theoretically when the inertial and streamline-curvature effects are moderate but not negligible as it is the case for roller pumps and the gastrointestinal tract. It is found that the pumping performance increases with increasing wall curvature and is decreased by inertial effects except at high squeeze. As in the inertia-free, infinite wavelength case there is a backwards flow (reflux) near the moving walls which is enhanced by both the inertial and curvature effects. Under certain conditions, there are boluses of fluid moving at the wave speed as if they were trapped by the wave. The range of this trapping is decreased by inertial effects and increased by curvature effects.