Kapillærtilstrømning

Kapillærtilstrømning is a term in fluid dynamics referring to the movement of a liquid into a narrow space, such as a capillary tube or porous material, due to the combined effects of surface tension and adhesion. This phenomenon is driven by the forces between the liquid molecules themselves (cohesion) and the forces between the liquid molecules and the solid surface (adhesion). When the adhesive forces between the liquid and the solid are stronger than the cohesive forces within the liquid, the liquid will tend to "wet" the surface and be drawn upwards.

The height to which a liquid will rise in a capillary tube is inversely proportional to the radius of the tube. This means that narrower tubes will exhibit a greater capillary rise. The principle of capillary action is observed in various natural and man-made systems. In nature, it plays a crucial role in how water is transported from the soil up into plants through their xylem tissues. It also contributes to the wicking effect seen in materials like paper towels or sponges, where liquids are absorbed and distributed.

In engineering, capillary action is utilized in applications such as ink delivery systems in pens, the operation of certain types of thermometers, and in chromatographic techniques for separating chemical substances. Understanding kapillærtilstrømning is essential for designing and optimizing processes involving fluid transport in confined spaces.