| Abstract: | The effects of scalariform perforation plate thickness and anglewithin vessel elements of Liriodendron tulipifera were studiedwith a computational fluid dynamical model. The pressure gradientand hence resistance to flow through the plate increased asthe perforation plate increased in thickness. Increasing theangle of the plate relative to the axis of the vessel (samenumber of pores) also increased the pressure gradient alongthe modelled cell. For the model matching the actual vesselelement, the plate contributed 8% to the flow resistance ofthe vessel element. This contribution increased only to 11%for doubled plate thickness, and to 14% for a plate at an angleof 60° to the vessel axis. The perforation plate alteredthe velocity profile across the vessel element, but to a differentextent depending on the angle of the plate. A plate at an acuteangle to the vessel axis has little effect on the paraboloidprofile as found upstream from the plate, while obtuse angleplates change the flow profile such that fluid through poresnear the wall is accelerated to a greater velocity than foundin the centre of the cell. Key words: Conductance, perforation plate, vessel, water flow |
