When performing cavitation observations at model scale it is standard at HSVA and also worldwide to use stroboscopic light for freezing the propeller’s motion.
This is a pity since a large amount of additional information is hidden in the dynamics of cavitation that happens between the flashes of the strobe. Especially for the judgment of cavitation aggressiveness with respect to erosion, for the elaboration of remedies against too high pressure pulses or for deeper insight into phenomena like tip vortex bursting this information would be valuable.
To get access to this additional information in critical cases, different High Speed Video (HSV) cameras are available at HSVA. Frame rates up to 5000 fps at full resolution are possible. Special illumination techniques are available to provide the enormous amount of light required for those cameras. Simultaneous recording of measuring values such as forces, hull pressures, or whatever might be of interest, is possible with up to eight channels.
- Observation of Complete Cavitation Dynamics
- Better Understanding of Pressure Pulse Generation
- Better Assessment of Cavitation Aggressiveness
A demonstration piece of a container ship propeller cavitating in HYKAT behind the complete ship model at 30 revs per second and recorded with 5000 frames per second can be checked out here.