Related Experiment Video
Updated: May 22, 2025
09:00
High Throughput Analysis of Liquid Droplet Impacts
Published on: March 6, 2020
6.3K
Droplet Impact Behavior on Convex Surfaces with a Circumferential Wettability Difference.
Taku Ishikawa1, Yutaka Yamada2, Kazuma Isobe2
1Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Kita-ku, Okayama 700-8530, Japan.
Langmuir : the ACS Journal of Surfaces and Colloids
|March 13, 2025
Summary
Controlling droplet impact on curved surfaces with varying wettability is crucial for applications like cooling and de-icing. This study reveals how wettability differences drive droplet behavior, enabling better control over bouncing and spreading.
Area of Science:
- Fluid Dynamics
- Surface Science
- Materials Science
Background:
- Controlling droplet impact is vital for applications such as splay cooling and icing prevention.
- Previous research explored droplet impact on superhydrophobic curved and flat surfaces, noting shorter contact times.
- Limited studies exist on droplet impact on curved surfaces with wettability differences, a promising area for droplet control.
Purpose of the Study:
- To investigate droplet impact behavior on curved surfaces with varying wettability (hydrophilic to superhydrophobic).
- To explore the influence of impact velocity, cylinder diameter, and rotation angle on droplet dynamics.
- To understand how wettability differences drive droplet deformation and movement on curved substrates.
Main Methods:
- Conducted droplet impact experiments on copper cylinders with controlled circumferential wettability.
- Varied parameters including impact velocity, cylinder diameter (4 and 6 mm), and rotation angle.
- Classified droplet behavior into four types: bounce, bounce and split, attach, and attach and split.
Main Results:
- Droplets impacting the wettability boundary exhibited asymmetric deformation and moved towards the hydrophilic side due to the wettability gradient.
- Identified four distinct droplet behaviors: bouncing, bouncing with splitting, attachment, and attachment with splitting.
- Successfully estimated droplet attachment or bouncing using maximum spreading width on flat substrates, Weber number, and rotation angle, aligning with experimental outcomes.
Conclusions:
- Wettability differences on curved surfaces effectively drive droplet behavior, offering a mechanism for droplet control.
- The study provides a framework for predicting droplet impact outcomes on such surfaces based on key parameters.
- Findings contribute to the design of surfaces for advanced applications requiring precise droplet manipulation.
More Related Videos
Related Concept Videos
01:13Contact Angle
11.6K
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces.
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
11.6K
02:57Surface Tension, Capillary Action, and Viscosity
27.4K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
27.4K
01:22Surface Tension of Fluid
203
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
203
01:30Impact
130
Impact occurs when two bodies collide, leading to the application of impulsive forces between them. Analyzing impact mechanics involves considering two colliding particles moving along a line known as the line of impact, which passes through their centers and is perpendicular to the contact plane.
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...
130
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
01:16Surface Tension and Surface Energy
1.3K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
1.3K