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Experimental investigation of impact-induced bubble dynamics
This project aims to experimentally study the dynamic response of bubbles to an external impulse. Impact-induced bubble dynamics observed for controlled initial conditions can help us model and identify the underlying mechanisms of traumatic brain injury and cavitation-induced damage. The main objectives include improving the in-house drop weight impact testing setup (the drop tower), high-speed imaging of bubbles and comparison with the theoretical model. The results will give insights into how single or multiple bubbles behave under extreme loading conditions.
Keywords: bubbles, impact testing, fluid dynamics
Gas bubbles undergo volumetric oscillations upon perturbation from their equilibrium state. Such oscillations can be observed by changing the pressure in the medium surrounding the bubble. Drop-weight impact testing systems typically study material response to impulsive loads. This project employs the “drop-tower” to impact a fluid-filled container causing pressure fluctuations, which mimic those induced by acoustic driving or hydrodynamic flows. The pressure experienced by a bubble inside the chamber can be measured using appropriate acceleration and pressure sensors for further characterization. Yield-stress fluids can trap small bubbles for a long time. The radial oscillations of a spherical bubble in a low-yield-stress fluid are comparable to those in a Newtonian medium. Carbopol is one such yield-stress fluid, which makes it a good candidate for controlled experiments.
Gas bubbles undergo volumetric oscillations upon perturbation from their equilibrium state. Such oscillations can be observed by changing the pressure in the medium surrounding the bubble. Drop-weight impact testing systems typically study material response to impulsive loads. This project employs the “drop-tower” to impact a fluid-filled container causing pressure fluctuations, which mimic those induced by acoustic driving or hydrodynamic flows. The pressure experienced by a bubble inside the chamber can be measured using appropriate acceleration and pressure sensors for further characterization. Yield-stress fluids can trap small bubbles for a long time. The radial oscillations of a spherical bubble in a low-yield-stress fluid are comparable to those in a Newtonian medium. Carbopol is one such yield-stress fluid, which makes it a good candidate for controlled experiments.
The main goal of the project is to experimentally characterize impact-induced bubble dynamics through high-speed imaging. This can further be divided into the following sub-tasks that may be undertaken by the student to complete the project.
1. Improve the drop-tower setup and incorporate pressure sensors.
2. Characterize the typical response of the impact testing system.
3. Generate bubbles inside a Carbopol sample using a laser or by injecting air.
4. Measure bubble dynamics in the test sample using a high-speed camera and appropriate image processing.
5. Compare the experimental results with the Rayleigh-Plesset equation for a single bubble.
6. Extend the study for multiple bubble configurations.
The main goal of the project is to experimentally characterize impact-induced bubble dynamics through high-speed imaging. This can further be divided into the following sub-tasks that may be undertaken by the student to complete the project.
1. Improve the drop-tower setup and incorporate pressure sensors. 2. Characterize the typical response of the impact testing system. 3. Generate bubbles inside a Carbopol sample using a laser or by injecting air. 4. Measure bubble dynamics in the test sample using a high-speed camera and appropriate image processing. 5. Compare the experimental results with the Rayleigh-Plesset equation for a single bubble. 6. Extend the study for multiple bubble configurations.
Please send your CV/resume and transcript of records in PDF format via email to ppatel@ethz.ch.
Feel free to contact me for more details! :)
Please send your CV/resume and transcript of records in PDF format via email to ppatel@ethz.ch. Feel free to contact me for more details! :)
