Experimental determination of pressures and velocities in plant xylem
Abstract
This study reports on the experimental modeling of fluid flow in plant xylem. Three experiments were conducted to determine pressures and velocities in the conducting vessels of the xylem portion of a plant using corn syrup as the working fluid and Plexiglas tubing as the test section. The first experiment was performed using a straight duct to model the flow in a xylem vessel without any obstructions. The second experiment was performed using a 5-pore perforation plate as an obstruction in a straight duct. This perforation plate was kept at an angle of 23 degrees relative to the vessel axis to match the fluid flow through a perforation plate found in the plant species Liriodendron tulipifera. In the third experiment, a 20-pore perforation plate was used to match the vessels of Liquidambar styraciflua. This plate was placed at an angle of 12.7 degRees To verify the flow behavior, the experimental results were compared with a numerical simulation using NEKTON, a computational fluid dynamics package. Experimental results and the numerical results agreed with each other. In the experiments involving the 20-pore perforation plate, the average loss coefficient was 86,300 over the range {dollar}\rm 0.2 < Re\sb{D} < 0.5.{dollar} The results of this work also consisted of plots of streamlines, velocity distributions, and pressure within the xylem.