Capillary-gravity wave scattering from barriers with pinned contact lines

带有固定接触线的障碍物的毛细重力波散射

• 批准号: 2306106
• 负责人: Likun Zhang
• 金额: $ 30.17万
• 依托单位: University of Mississippi
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2306106&HistoricalAwards=false
• 关键词: Capillary; gravity; wave; scattering; barriers

Capillary-gravity waves are waves traveling along free surfaces of liquids and are often confined in a narrow channel. The proposed research is designed with the goal of achieving an improved understanding of the fundamental fluid physics underlying surface wave interactions with a rigid wall. The three-phase liquid-air-solid boundary influences the liquid behavior, which is important in laboratory studies and also in industrial applications, for instance, the dynamics of drops attached to a solid wall, liquid oscillations in closed basins, liquid globes and lenses attached to thin wire loops, liquid cylinders stabilized by helical wires, and wave propagation and flows in open narrow channels. The understanding provided by this research will enable the development of new designs and models that will lead to more efficient liquid management involving minimal solid contact. The results will be applicable to engineering areas including condensation heat transfer, liquid-gas contacting processes, and chemical engineering applications, as well as applications in biology and biotechnology. The approaches developed from this project will also provide new methods for measuring and modeling fluid behavior involving three-phase boundaries. The project will also contribute to the preparation and diversification of the STEM workforce involving undergraduates, graduate students, and a mid-career stage faculty member. The proposed research will use laboratory and computational experiments to improve the understanding of the fundamental fluid physics underlying the scattering of travelling capillary-gravity waves from a surface-intersecting rigid barrier, where contact lines pin the free surface of the liquid at a barrier's edge. The laboratory experiments will use an acoustic method of airborne ultrasound reflected out the water surface to measure the amplitude of capillary-gravity waves. The computational experiments will concern inviscid linear waves in incompressible and irrotational flow by finite-element simulations using commercially available software. Specifically, the project will study (i) contact line effects in the transition from gravity wave scattering to capillary wave scattering, (ii) the dependence of wave scattering on the barrier's geometric parameters, and (iii) the effect of menisci near the barrier walls where the liquid surface is curved. Understanding how contact lines at three-phase boundaries influence the dynamics of a free liquid surface is essential in surface-tension dominated fluid dynamics. Prior studies involving contact line effects on capillary dynamics focused mainly on the frequency dependence and the damping of standing-wave modes. In contrast, the proposed research will fill the gap of knowledge in capillary-gravity wave scattering from rigid structures with contact line effects. Since the 1960s theoretical studies have attempted to predict the contact line effects on capillary-gravity wave scattering, but progress has been hindered by the limitation of ideal assumptions made in the models, and by the lack of experimental data for the understanding of the fluid physics. The proposed laboratory experiments will provide the first quantitative results on the effect of contact lines on the scattering. The laboratory and computational experiments should systematically improve the knowledge on the fluid physics of the scattering and yield new insights on the influence of contact lines and menisci, and on the dependence on wave and structure parameters.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

毛细血管刺激的波是沿着液体的自由表面传播的波，通常被限制在狭窄的通道中。拟议的研究旨在实现对与刚性壁相互作用基础的基本流体物理学的理解。三相液体 - 空气固体边界会影响液体行为，这在实验室研究以及工业应用中很重要，例如，连接到固体壁上的滴动力学，封闭盆地的液体振荡，液体地球仪和透镜连接到薄电线上的液体透镜，液体圆柱体稳定，由螺旋线和波动的狭窄通道稳定，并在狭窄的狭窄通道中稳定。这项研究提供的理解将使新设计和模型的开发能够开发，从而导致更有效的液体管理，涉及最小的固体接触。结果将适用于工程领域，包括冷凝传热，液态气接触过程和化学工程应用以及生物学和生物技术的应用。该项目开发的方法还将为涉及三相边界的流体行为提供新的方法。该项目还将有助于涉及本科生，研究生和职业阶段的教职员工的STEM劳动力的准备和多样化。 拟议的研究将使用实验室和计算实验来提高对从表面交流的刚性刚性屏障散射的基本液体物理学的理解，在此，接触线将液体的自由表面固定在屏障边缘。实验室实验将使用一种反射水面的空气传播的声学方法，以测量毛细血管刺激波的幅度。计算实验将涉及使用市售软件通过有限元模拟不可压缩和无关的线性波。具体而言，该项目将研究（i）从重力波散射到毛细管波散射的过渡中的接触线效应，（ii）波散射对屏障几何参数的依赖性，以及（iii）在液体表面弯曲的屏障壁附近的弯板效应。了解三相边界处的接触线如何影响自由液体表面的动力学对于表面张力主导的流体动力学至关重要。涉及接触线对毛细管动力学的效果的先前研究主要集中在频率依赖性和站立模式的阻尼上。相比之下，拟议的研究将填补具有接触线效应的刚性结构的毛细血管重力波散射的知识空白。 自1960年代以来，理论研究试图预测接触线对毛细血管 - 重力波散射的影响，但是由于模型中理想的假设的局限性以及缺乏对流体物理学理解的实验数据的限制，进步受到了阻碍。提出的实验室实验将为接触线对散射的影响提供第一个定量结果。实验室和计算实验应系统地提高散射流体物理的知识，并就接触线和半月障碍的影响以及对波浪和结构参数的依赖产生新的见解。该奖项反映了NSF的法定任务，并通过使用基金会的知识优点和广泛的影响来评估NSF的法定任务，并被认为是值得的。