Case Study: Fluid Dynamics

Bouncing Droplets of Water–Fluid Dynamics with Chronos High-Speed

How can we use high-speed imaging to capture and analyze the microsecond rotational dynamics of bouncing water droplets—something traditional cameras fail to reveal?

Read Full Research Paper

Application: Fluid Dynamics | Surface Interaction | Experimental Physics

Industry: Academia & R&D

Camera Used: Chronos 1.4

Challenge

The challenge was to capture and analyze rapid droplet rotation driven by surface tension, using high-speed imaging to measure motion frame by frame and validate fluid dynamics models.

In a collaborative research project featured in Communications on Analysis and Computation (Vol. 6, 2025), a team of physicists and students from Green Hope High School, University of Chicago, and Cary Academy set out to explore an unusual fluid dynamics phenomenon: the spontaneous rotation of water droplets after bouncing off patterned surfaces. Understanding the rotational behavior of water droplets required:

High-speed precision imaging of motion occurring within milliseconds.
Accurate frame-by-frame analysis of angular velocity
A setup compact enough for academic lab environments.
The ability to track subtle changes in droplet shape and motion dynamics

Traditional video recording methods lacked the resolution and speed necessary to capture these micro-scale dynamics in real time.

The Chronos camera gave us the clarity and speed we needed to validate a simplified yet powerful mathematical model.

Michael Tsynkov

Lead Author

Solution

The team deployed a Chronos 1.4 high-speed camera, set at 3,030 FPS, to capture droplet behavior as it bounced off a hydrophilic pattern etched into a hydrophobic soot-coated glass surface.

Setup Highlights:

Controlled droplet release from 4 inches above the test surface
Etched patterns using toothpicks to create 2, 3, and 4-pronged designs
Lighting system with multiple high-lumen flashlights for shadow reduction.
Tracking with glitter particles inside each droplet to measure angular rotation.

Key Findings:

Theoretical Validation

Experimental data showed a strong positive correlation between angular velocity and the semi-major axis of the droplet, confirming theoretical predictions.
The simplified oblate spheroid mathematical model proved qualitatively accurate as the discrepancy between theoretical and experimental angular velocity values remains within 45%.

Pattern Influence

Different etched patterns (two-pronged, three-pronged, and four-pronged) produced similar angular velocities, and the resulting droplet shape also remained consistent.
Angular velocity was identified as the dominant factor influencing droplet deformation, specifically the semi-major axis of the oblate spheroid.

Chronos Advantage
The Chronos camera’s portability, high frame rate, and ease of use made it ideal for:

Capturing ultra-fast droplet motion
Pixel-based calibration with high precision
Conducting repeatable experiments in a small lab environment

Summary

Researchers investigated the rotation of water droplets bouncing off hydrophilic patterns on hydrophobic surfaces to better understand the interplay of surface tension and centrifugal forces. Using a Chronos high-speed camera recording at 3,030 FPS, they precisely captured and analyzed the droplet motion, providing experimental validation for a theoretical model.

The study revealed that angular velocity, rather than pattern shape, was the key factor driving the observed deformation in droplet shape. Experimental data showed strong agreement with theoretical calculations, with results aligning within approximately 45% accuracy.

The Chronos camera’s high frame rate, portability, and precision made it an ideal tool for this type of fluid dynamics research. Its ability to deliver detailed, high-speed visualization not only advanced this study but also demonstrates its value for material science, fluid mechanics, engineering applications, and academic research.

Read Full Research Paper

About

Kron Technologies Inc. is a Canadian high-speed imaging system design and manufacturing company, located in the heart of the Greater Vancouver Area (British Columbia). Kron was founded by owner and visionary Engineer David Kronstein who wanted to make high-speed imaging accessible to everyone.