首页> 外文期刊>Nature >Reducing the contact time of a bouncing drop
【24h】

Reducing the contact time of a bouncing drop

机译:减少弹跳的接触时间

获取原文
获取原文并翻译 | 示例
           

摘要

Surfaces designed so that drops do not adhere to them but instead bounce off have received substantial attention because of their ability to stay dry, self-clean and resist icing. A drop striking a non-wetting surface of this type will spread out to a maximum diameter and then recoil to such an extent that it completely rebounds and leaves the solid material. The amount of time that the drop is in contact with the solid-the 'contact time'-depends on the inertia and capillarity of the drop, internal dissipation and surface-liquid interactions. And because contact time controls the extent to which mass, momentum and energy are exchanged between drop and surface, it is often advantageous to minimize it. The conventional approach has been to minimize surface-liquid interactions that can lead to contact line pinning; but even in the absence of any surface interactions, drop hydrodynamics imposes a minimum contact time that was conventionally assumed to be attained with axisymmetrically spreading and recoiling drops. Here we demonstrate that it is possible to reduce the contact time below this theoretical limit by using superhydrophobic surfaces with a morphology that redistributes the liquid mass and thereby alters the drop hydrodynamics. We show theoretically and experimentally that this approach allows us to reduce the overall contact time between a bouncing drop and a surface below what was previously thought possible.%本期封面所示为一个水滴落在一只闪光蝶的防水翅膀上。能够保持干燥、有自清洁功能或能防结冰的表面有很多用途。袭击这种表面的液滴往往会展开,然后在最后弹起之前回缩。很多应用都能受益于减小液滴和表面之间的接触时间,这种现象被普遍假设是当撞击的液滴发生对称变形时出现的。现在,Kripa K. Varanasi及同事发现,在一个具有能重新分配液体质量、以使其不再展开和对称回缩的形态的超憎水性表面上,液滴弹开的速度会更快。理论和实验都证实,这种办法能将一个弹起的液滴和一个表面之间的接触时间大大缩短,超过过去被认为可能做到的极限。
机译:经过精心设计的表面不会掉落而是滴落下来,因为它们具有干燥,自清洁和防结冰的能力,因此备受关注。碰到这种非润湿表面的液滴将散布到最大直径,然后反冲到一定程度,使其完全回弹并留下固体物质。液滴与固体接触的时间(“接触时间”)取决于液滴的惯性和毛细作用,内部耗散以及表面与液体的相互作用。并且由于接触时间控制着液滴,表面之间交换质量,动量和能量的程度,因此将其最小化通常是有利的。传统方法是尽量减少可能导致接触线钉扎的表面-液体相互作用。但是即使在没有任何表面相互作用的情况下,液滴的流体动力学也施加了最小的接触时间,这通常被认为是通过轴对称的扩散和回弹液滴实现的。在这里我们证明,通过使用具有重新分布液体质量从而改变液滴流体动力学的形态的超疏水表面,可以将接触时间减少到理论极限以下。我们在理论上和实验上都表明,这种方法可以使弹跳液滴与表面之间的总接触时间减少到以前认为的可能范围以下。%本期封面显示为一个水滴落在一只闪光蝶的防水翅膀上。能够保持干燥,有自清洁功能或能防结冰的表面有很多用途。突然这种表面的经常会展开,然后在最后弹起之前回缩。现在,Kripa K. Varanasi及同事发现,在一个具有能重新分配液体质量,以替换不再的情况下,表面之间的接触时间,这种现象被普遍假设是当碰撞的起点发生对称变形时出现的。理论和实验都证实,这种方法能将一个弹起的位移和一个表面之间的接触时间大大缩短缩短,超过过去被认为可能做到的极限。

著录项

  • 来源
    《Nature》 |2013年第7476期|385-388a3|共5页
  • 作者单位

    Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02155, USA;

    Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA,Present address: 3M Purifications, Inc., 400 Research Parkway, Meriden, Connecticut 06033, USA;

    Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;

    Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号