一种二元复合结构聚合物减阻涂层的制备

为了通过表面形貌构型实现水下减阻,基于Benard对流理论制备了一种具有二元复合结构的聚合物涂层。采用高压空气喷涂工艺,将涂料喷涂在基体材料上形成液膜;液膜固化后,亚mm级和μm级二元复合的形貌结构在涂层表面自发形成。对液膜体系中温度变化及物料迁移分析的结果表明:溶剂蒸发导致了温度梯度和表面张力梯度的出现,由此引发的界面流和界面变形,是二元复合结构表面形貌形成的主要原因。在清华大学SKLT-1小型高速水洞中,对涂层的减阻性能进行了初步测试。测试结果表明,涂层具有显著的减阻效果。

Fabrication of binary structured surface for drag reduction

In order to reduce the skin friction drag of underwater vehicles with specially designed surface,a novel method for the fabrication of binary structured surface was proposed based on Benard convection.A mixture was coated on a substrate through a specially developed spray-painting apparatus,and the polymer coating with submilli-microscale binary structured surface formed spontaneously after the solidification of wet coating film.Experiments were performed and computational fluid dynamic methods were conducted to investigate the formation mechanism of binary structure surface.According to the results,Benard convection and interfacial deformation driven by the gradients of temperature and surface tension due to solvents evaporation play a determinant role in the formation process of surface topography.To evaluate the drag reduction property,samples with fabricated surface were tested in a water tunnel,and remarkable drag reduction performance was obtained.