On hydraulics of capillary tubes

Modelling Adiabatic Capillary Tubes: A Critical Analysis

Gravity-driven slug motion in capillary tubes

The velocity of a liquid slug falling in a capillary tube is lower than predicted for Poiseuille flow due to presence of menisci, whose shapes are determined by the complex interplay of capillary, viscous, and gravitational forces. Due to the presence of menisci, a capillary pressure proportional to surface curvature acts on the slug and streamlines are bent close to the interface, resulting in...

Capillary rise in tubes with sharp grooves

Liquid in grooved capillaries, made by e-ginserting a plate in a cylindrical tube, exhibits unusual spreading and flow properties. One example is capillary rise, where a long, upward tongue on top of the usual meniscus has been observed along the groove. We attribute the underlying mechanism to a thermodynamic instability against spreading for a (partial

Rates of Spontaneous Movement of Water in Capillary Tubes

The neglect of inertia terms and assumption of Poiseuille's flow approximations in describing the motion of a liquid with a free surface in narrow passages are inappropriate for certain motions. This is demonstrated with experiments in which the rates of spontaneous rise of a meniscus in an empty capillary tube, when one end is suddenly contacted with a pool of water, were determined with the a...

Computational studies of emergent autowave phenomena in capillary tubes

Travelling autowaves are a particular feature of nonlinear active media. Those waves are characteristic of action potential propagation in cardiac and neuronal tissue, while qualitative analogous phenomena can be produced in man–made physico–chemical laboratory experiments, such as the Belousov–Zhabotinsky reaction (BZR). The waves can appear in several forms: straight, curved and circular fron...