%A XU Tianyu,ZHANG Lixiang* %T Fluid mechanics modeling and flow characteristics analysis of secondary wall thickening reticulated vessels in vascular plants %0 Journal Article %D 2020 %J Journal of Drainage and Irrigation Machinery Engin %R 10.3969/j.issn.1674-8530.19.0093 %P 76-82 %V 38 %N 1 %U {http://zzs.ujs.edu.cn/pgjx/CN/abstract/article_2832.shtml} %8 2020-01-25 %X Effects of inner diameter, number of helical curls, spacing of helical curls, helical curl height and width in secondary wall thickening reticulated vessels on water transport in the xylem of vascular plants were analyzed in terms of pressure drop and equivalent hydraulic loss coefficient(flow resistance coefficient)by using computational fluid dynamics(CFD)combined with the Bernoulli equation to study micro-flow mechanism in the vessels. The results showed that the total pressure drop and flow resistance coefficient were increased by 16.34% and 26.45%, respectively, with increasing number of helical curls. With increasing helical curl spacing, however, the total pressure drop and flow resistance coefficient were decreased by 5.49% and 9.83%. The total pressure drop and flow resistance coefficient rose by 33.89% and 57.96% as the helical curl height was increased. Additionally, the total pressure drop and flow resistance coefficient ascended by 9.56% and 15.30% with increasing helical curl width. The interaction between helical reticulated curl structure and flow recirculation region in the vessels, especially the recirculation region, was mainly responsible for the effects of the secondary wall thickening on the water transport. Compared with three different thickening vessels, the helical reticulated curl vessel was subject to the greatest flow resistance, and the helical curl vessel was with the smallest resistance, but the flow resistance in the annular vessel was in between. The flow resistance was proportional to vessel inner diameter in three thickening vessels. The larger the inner diameter of a thickening vessel, the closer the transport efficiency of the vessel to that of an ideal smooth vessel.