Insights into the Effect of Bordered Pit Structure on Water Transport Performance

Abstract

In plants, the transport of water is mediated by vessel and pit structures, which are integral to this physiological process. Among the various pit types, the bordered pit is recognized as particularly effective. To investigate the impact of structural parameters on fluid flow performance, a microstructural fluid dynamics model of plant tissue was developed employing finite element simulation. This model integrates laminar flow and porous media physics within a unified framework, and the computed results agreed with existing experimental and numerical studies. An analysis was conducted to assess variations in pressure drop, flow rate, and flow resistance as a function of several parameters, including pit aperture diameter, torus diameter, pit diameter, pit depth, margo thickness, porosity, and micropore diameter. The results demonstrate that overall flow resistance decreases with increases in pit diameter, pit aperture diameter, pit depth, porosity, and micropore diameter, whereas it increases with larger torus diameter and margo thickness. Notably, parameters associated with the margo exert a particularly pronounced effect on water transport characteristics. This study provides a mechanical rationale elucidating the structure-function relationship governing water transport in coniferous plants and offers theoretical foundations for the design of biomimetic microfluidic devices and plant-inspired water-conducting materials.