狂奔的气泡 狂奔的气泡
Jian H Guan1, Saiful I Tamim1, Connor W Magoon1
1Department of Mathematics, University of North Carolina, Chapel Hill, NC, USA.
Nature communications
|February 12, 2025
概括
新发现的狂奔的气泡通过共振形状振荡在表面上自行推进. 这种新的移动机制在流体动力学和软机器人学中提供了多方面的应用.
科学领域:
- 流体动力学 流体动力学
- 软物质物理学 软物质物理学
- 非牛顿流体力学 不牛顿流体力学
背景情况:
- 气泡表现出复杂的动态,在各种科学和工业领域都有应用.
- 了解泡推进对于推进流体操纵和运输技术至关重要.
研究的目的:
- 介绍和描述一种新的气泡自动推进机制,称为"跑".
- 探索这些活跃泡的可调节轨迹模式和潜在物理.
- 为了展示的气泡机车运动的潜在技术应用.
主要方法:
- 在垂直振动的液体室中对气泡的实验研究.
- 在不同的外部强迫条件下分析气泡轨迹动态.
- 开发一个最小的振荡器模型,以捕捉狂奔现象的普遍性.
主要成果:
- 气泡自发地在水平表面上表现出"的"运动.
- 通过外部强迫观察和控制了不同的轨迹模式 (直线,轨道,跑动).
- 推进机制依赖于共振形状振荡和惯性力,不同于流.
结论:
- 狂奔的气泡代表了一个强大的,普遍的自我推进机制,适用于各种气泡-表面相互作用.
- 这一发现为微流体,传热,机器人和表面清洁等领域的创新应用开辟了道路.
- 该研究强调了活性物质系统在先进技术解决方案中的潜力.
相关概念视频
01:13Excess Pressure Inside a Drop and a Bubble
1.6K
The shape of a small drop of liquid can be considered spherical, neglecting the effect of gravity. This drop can further be considered as two equal hemispherical drops put together due to surface tension. The forces acting on the spherical drop are due to the pressure of the liquid inside the drop, the pressure due to air outside the drop, and the force due to the surface tension acting on the two hemispherical drops.
1.6K
01:18Rise of Liquid in a Capillary Tube
1.3K
When very thin cylindrical tubes, called capillaries, are dipped in a liquid, the liquid rises or falls in the tube compared to the surrounding liquid. This phenomenon is called capillary action. Capillary action occurs due to the combination of two opposing forces: the cohesive forces of the liquid, which cause it to stick to itself and form a rounded shape, and the adhesive forces between the liquid and the walls of the container, which cause the liquid to be attracted to the container walls.
1.3K
01:19Escape Velocities of Gases
887
To escape the Earth's gravity, an object near the top of the atmosphere at an altitude of 100 km must travel away from Earth at 11.1 km/s. This speed is called the escape velocity. The temperature at which gas molecules attain the rms speed, which is equal to the escape velocity, can be estimated by using the equation for the average kinetic energy of the gas molecules. According to the kinetic theory of gas, the average kinetic energy of the gas molecules is proportional to its...
887
01:29Gradually Varying Flow
31
Gradually varying flow (GVF) in open channels describes situations where water depth changes slowly along the channel due to factors like non-uniform bed slope, channel shape variations, or obstructions. This flow type occurs when the depth adjusts gradually to balance gravitational forces, shear forces, and energy requirements, resulting in a low rate of depth change.Characteristics of Gradually Varying FlowGVF is commonly observed in natural streams, rivers, and canals, where flow depth...
31
01:24Rapidly Varying Flow
48
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
48
01:09Deriving the Speed of Sound in a Liquid
469
As with waves on a string, the speed of sound or a mechanical wave in a fluid depends on the fluid's elastic modulus and inertia. The two relevant physical quantities are the bulk modulus and the density of the material. Indeed, it turns out that the relationship between speed and the bulk modulus and density in fluids is the same as that between the speed and the Young's modulus and density in solids.
The speed of sound in fluids can be derived by considering a mechanical wave...
The speed of sound in fluids can be derived by considering a mechanical wave...
469