材料表面润湿性调控及减阻性能研究

设计合成不同结构的自组装分子,使其可以在不改变表面粗糙度的情况下改变表面的润湿性能;利用低表面能涂层修饰粗糙表面得到超疏水表面.采用流变仪和水洞试验分别在层流和湍流流动状态下测试了具有不同润湿行为的亲、疏水材料的减阻性能.结果表明:在层流流动状态,随着不同表面的接触角从13°增加到45°、113°和161°,减阻率随之从1.8%增大到7.2%、7.9%和14.9%;在湍流流动状态下,自组装涂层接触角为13°、45°和113°的三组模型的平均减阻率为0.8%、1.9%和6.8%,最大减阻率分别可达3.6%、9.2%和18.0%.两种流体流动中均存在材料表面水接触角增加减阻效率增大的行为.

Fabrication and Drag Reduction of Controllable Wetting Surfaces

On the one hand,3 types of dopamine based copolymers were synthesized which can vary the surface wettability of smooth surface, on the other hand,superhydrophobic surface was fabricated by coating low surface energy material on rough surface. The drag reduction properties of samples with different wettability were measured in laminar flow and turbulent flow by rheometer and water tunnel equipments,respectively. It was found that drag reduction of samples increased from 1.8% to 7.2%,7.9% and 14.9% with an increase of contact angles from 13° to 45°,113° and 161° in the laminar flow,and the mean values of drag reduction of the first three samples increased from 0.8% to 1.9% and 6.8% (corresponding maximum values were 3.6%,9.0% and 18%,respectively) in turbulent flow. It was concluded that the increase of water contact angle of material surface resulted in an increase of drag reduction in both laminar and turbulent flow.