Two-Dimensional Peristaltic Flow in Curved Channels.

Particle dispersion in two-dimensional peristaltic flow

Abstract Particle dispersion in a two-dimensional peristaltic flow with zero pressure rise is investigated. It is found that, depending on the degree of occlusion of the peristalsis, particle motion can be forward or retrograde. Dispersion of a group of particles is quantified using the mean particle position and the variance around this. The degree of occlusion of the wave can be used to promo...

Streamline topologies of two-dimensional peristaltic flow and their bifurcations

Streamline patterns and their local and global bifurcations in a two-dimensional peristaltic flow for an incompressible Newtonian fluid have been investigated. An analytical solution for the stream-function is found under a long-wavelength and low-Reynolds number approximation. The problem is solved in a moving coordinate system where a system of nonlinear autonomous differential equations can ...

Particle motion in unsteady two-dimensional peristaltic flow with application to the ureter.

Particle motion in an unsteady peristaltic fluid flow is analyzed. The fluid is incompressible and Newtonian in a two-dimensional planar geometry. A perturbation method based on a small ratio of wave height to wavelength is used to obtain a closed-form solution for the fluid velocity field. This analytical solution is used in conjunction with an equation of motion for a small rigid sphere in no...

Stokes flow in a junction of two-dimensional orthogonal channels

Quantum Inequalities in Curved Two Dimensional Spacetimes

In quantum field theory there exist states for which the energy density is negative. It is important that these negative energy densities satisfy constraints, such as quantum inequalities, to minimize possible violations of causality, the second law of thermodynamics, and cosmic censorship. In this paper I show that conformally invariant scalar and Dirac fields satisfy quantum inequalities in t...