Equipment. Cavitation Tunnel.

DYNAMOMETER

The dynamometer is installed on the upper part of the working section in the tunnel. The propeller is mounted on the submerged shaft of the dynamometer. The main characteristics measured are: thrust, torque, vertical and horizontal forces and rate of revolutions. The electric signals from all channels are digitalized and submitted to the acquisition program of the main computer.

 

TWO-COMPONENT LASER-DOPPLER ANEMOMETER

This 5-watt Argon laser anemometer has an optical unit splitting the source beam into two pairs of beams. The output is transmitted via optic fiber along to the probe, which has a convergent lens fitted to its end. This produces the volume of measurement at the cross-over point formed by the four beams. Four photo-multipliers receive the light signal reflected by the particles crossing the volume and transform it into electric pulses that enter a processor where they are turned into electrical Doppler signals containing the water speed information. A special 3D displacement mechanism with a remote control unit is connected to the computer to position the point of measurement.

 

PRESSURE TRANSDUCERS

These are used to measure pressure fluctuations at different locations above the propeller being tested. The computer performs data acquisition and FFT analysis of the spectra, producing a tabulated and graphical data output.

 

MEASUREMENT DEVICE FOR OXYGEN DISSOLVED IN THE WATER

This analyzer measures oxygen concentration in water. With these measurements and the saturation content at different temperatures, the percentage of dissolved oxygen is obtained. The range of measurement is up to 20 mg/l from 0 to 50 degrees Celsius.