Cavitation tunnel characterized by stable cavitation-nuclei-distributions.

In order to establish the necessary condition for such cavitation experiments in an open type cavitation tunnel, the cavitation nuclei distributions were carefully measured in the test water sampled from a fixed point in the stilling reservoir for a typical flow quantity, by means of a Coulter counter. It is worth noting that in the cavitation tunnel, the nuclei distributions scarcely change with time in the entire working period past the initial unstable period. The waiting time to stabilize the distribution is also defined.