Holographic investigation of cavitation phenomena in a high speed tunnel

Cavitation phenomena of a cylindrical body with a spherical nose were recorded holographically in a high speed water tunnel. Holograms were taken using a ruby pulsed laser. The results showed that bubbles with a diameter larger or equal to 5 microns practically do not occur upstream from the body. The holograms were also used to record the cavitation on the body. The effect of injecting polymers in the flow was studied. A solution of polymer Polyox WSR-31 was injected into the nose of the body. This polymer reduces the friction coefficient for flow around the body, if a turbulent boundary layer exists, and can suppress cavitation.