Cavitation is the formation of bubbles by the boiling of a fluid as a hydrofoil travels through it. Let the hydrofoil be located at a depth z, then Bernoulli's law in a gravitational field gives
The fluid in front of the hydrofoil is at rest, so
Solving for u gives
References
Brennen, C. E. Cavitation and Bubble Dynamics. Oxford, England: Oxford University Press, 1995. http://resolver.caltech.edu/CaltechBOOK:1995.001.
Knapp, R. T.; Daily, J. W.; and Hammitt, F. G. Cavitation. New York: McGraw-Hill, 1970.
Pearsall, I. S. Cavitation. London: Mills and Boon, 1972.
Weisstein, E. W. "Books about Cavitation." http://www.ericweisstein.com/encyclopedias/books/Cavitation.html.
Young, F. R. Cavitation. New York: McGraw-Hill, 1989.
