Experimental analysis of the interaction of adhering droplets for different arrangement of droplets under the influence of flow and surface vibration

流动和表面振动影响下不同液滴排列的附着液滴相互作用的实验分析

• 批准号: 459968952
• 负责人: Professor Dr.-Ing. Uwe Janoske
• 金额: --
• 依托单位: Fachgebiet Strömungsmechanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/459968952?language=en
• 关键词: Experimental; analysis; interaction; adhering; droplets

Because of the effects of contact angle hysteresis, droplets can stick to surfaces until a critical velocity of the gas flow is reached (e.g. droplet on the visor of a helmet). If a vibration of the surface is superposed, a reduction of the critical velocity can be observed leading to a transport in flow direction. If more than one droplet is present, coalescence of the droplets can be observed leading to the creation of liquid films. The detachment of droplets and the creation of films is a function of (i) the arrangement of the droplets, (ii) frequency and amplitude of the surface vibration, (iii) droplet volumina, (iv) liquid properties and (v) wetting behaviour (surface tension, contact angles). The relation should be examined for droplets in different arrangements. This should be done in an experimental approach. For the experiments flow channels are used which are connected to an electromagnetic shaker to generate controlled surface vibrations. The evaluation and analysis of the droplet movement is done by optical methods (shadowgraphy and PIV).

由于接触角滞后的影响，液滴可以粘在表面，直到达到气流的临界速度(例如，头盔面罩上的液滴)。如果表面的振动是叠加的，则可以观察到临界速度的降低，导致沿流动方向的输运。如果存在一个以上的液滴，则可以观察到液滴的合并导致液膜的形成。液滴的脱落和成膜是以下因素的函数：(I)液滴的排列，(Ii)表面振动的频率和幅度，(Iii)液滴的体积，(Iv)液体的性质和(V)润湿行为(表面张力、接触角)。应检查不同排列的液滴之间的关系。这应该以一种实验性的方法来完成。在实验中，使用了与电磁振动器相连的流动通道来产生受控的表面振动。用光学方法(阴影照相法和PIV法)对液滴的运动进行了评价和分析。