Image post processing of cavitation in an orifice at different water temperature.

Amplitude Spectrum of the upstream and downstream pressure fluctuations measured at several temperatures and s=1.65 (logarithmic scale on each of the axes).

The present activity focuses on the formation of cavitation in cold and hot water and in cryogenic fluid, characterized by strong variations in fluid properties caused by a change in temperature. Cavitation phenomenon is investigated in water and nitrogen flows in a convergent-divergent nozzle through pressure measurements and the optical visualization method. High-speed photographic recordings have been made, the cavitation phenomena evolution and the related frequency content are investigated by means of pixel intensity time series data. The results obtained concur with those obtained with the spectral analysis of the pressure signals. Study of computational methodologies is performed by using different cavitation models, for cavitating cryogenic flows taking into account nucleation and thermal effects. 

Numerical analysis (In-house code and commercial code with user routines):
- Traditional Fluids:

• Water Cavitating flow into the Nozzle.

• Cavitation in turbomachinery

• Diesel injection systems

- Cryogenic fluid:

• Nitrogen Cavitating flow into the Nozzle

• Hydrogen cavitating fluid over Naca profiles

Developement of Artificial Neural network for cavitation regime identification

- Test-case A: Water cavitating flow in an orifice 

- Test-case B: Nitrogen cavitating flow in an orifice

Experiments on:

- Test-case A: Water cavitating flow in an orifice

- Test-case B: Nitrogen cavitating flow in an orifice