Estimated Bubble Diameter
Air in clean water at 20°C · 0.30 m diffuser depth
Project 01 · Case study
Final bachelor project
Design and Experimental Investigation of a Bubble Curtain
Experimental bubble-curtain testing supported by a custom Python pipeline for extracting bubble size and motion from difficult high-speed footage.
Estimated Bubble Rise Speed
Production: approximately 1,350 bubbles/s across 19 nozzles
Project overview
One project, multiple operating conditions
Different nozzle diameters were tested across specific pressure ranges. Each configuration was recorded and analysed separately.
Media on this page · 2 mm nozzle · 1.6 barExperimental programme
The broader bachelor project investigated how operating conditions influence bubble-curtain behaviour.
Image challenge
Bubble overlap, merging, separation and changing shape made persistent tracking difficult.
Custom analysis
I created a Python workflow for segmentation, detection, classification and frame-to-frame comparison.
Image-analysis pipeline
How the detection pipeline worked
Each frame moved through boundary isolation, region filling and object classification before geometric measurements were extracted.
Three-frame tracking
Why three frames were enough
Longer sequences repeatedly redefined the same physical bubble as it merged, separated or changed shape.
Three consecutive frames retained useful displacement information while limiting unstable identity changes. Further analysis then produced representative diameter and velocity values.
Motion extraction
Tracking bubble movement
Matched regions were compared to estimate displacement between consecutive frames.
The vector field shows the dominant upward movement together with lateral motion, local interaction and uncertain matches caused by irregular bubble shapes.
Recorded evidence
Original and detected sequences
The paired videos show the raw image quality and the detections generated by the analysis pipeline.
Selected frames
One run, three example frames
These frames demonstrate one configuration only. The complete study included other nozzle and pressure combinations.
Engineering outcome
From imperfect footage to usable data
The workflow provided a transparent basis for estimating bubble diameter and velocity within the project constraints.
A stronger optical setup would improve tracking confidence. The selected method nevertheless produced a structured and reproducible analysis route.