1. Introduction to Cavitation

2. Why Study Cavitation?
Has been an important topic in engineering science for well over 100 years. Any device handling liquids is subject to cavitation.
Can adversely affect the performance of turbomachinery, the thrust of propulsion systems and the accuracy of fluid meters.
Noise, vibration and erosion occur in many applications

3. Why Study Cavitation?
Important in applications such as ultrasonic cleaning, homogenization of milk, enhanced chemical processes through coagulation, formation of suspensions and degassing of liquids.
Cavitation can be used to increase heat and mass transfer in liquids, to promote crystallization and to enhance various sonochemical reactions such as polymerization and polymer degradation.

4. Why Study Cavitation?
Biomedical applications include the removal of kidney stones and automated drug delivery to patients.
Important new applications in the pollution control area are of interest.
Plays a role in biomechanics, geomorphology and other topics in physics.

5. Cavitation in Biophysics
From SCIENCE VOL SEPTEMBER 2000

6. Spillway Damage Due to a Horseshoe Vortex

7. Vortex Damage in a Hydroturbine

8. Geomorphology
See Movie

9. Cavitation Can Occur in the Flow or Adjacent to a Boundary
On the surface of a Hydrofoil
Jet Flow

10. Fundamentals
The fundamental parameter in describing the physics of the process is the cavitation index, defined by
We can think of i as a performance boundary such that
   > i no cavitation effects
   < i cavitation effects such as performance degradation, noise, and vibration

11. US Navy Large Cavitation Channel
Water Tunnels
US Navy Large Cavitation Channel
3m X 3mTest Section
10 Stories High
SAFL Water Tunnel
0.19m X 0.19 m Test Section
1 Story High

12. Propeller Cavitation Japan The Netherlands PIV Imaging, Italy
Comparison of measurements
with numerical simulations,USA
PIV Imaging, Italy

13. Tip Vortex Cavitation
Wind tunnel and water tunnel simulations are used to study this problem experimentally. Experiments are supplemented with numerical simulations. Example shown is a NACA section with elliptic planform.
Wind tunnel Water tunnel

14. Observation of Singing Vortex
Slow Motion, 4500 fps
Pressure Slowly Decreasing

15. Supercavitating Vehicles
A joint venture between SAFL
and AEM
AEM: Stability and Control
SAFL: Physics of Ventilated
Flows
Sponsored by ONR

16. Ventilated Flow Studies- Supercavitation

17. looking for new applications
The Future
We are always
looking for new applications

18. For Further Information: