Engineer Steve has been sent to inspect a water
reservoir with a pipe acting as a water siphon. He would like to find
out if the pipe is installed properly so that cavitation will not occur
inside the pipe. If cavitation does occur, what
should he recommend to change the system? The dimensions of the system
are given in the figure.

Questions

Determine the pressure at point 2 for the current system. Find
the allowable height of the pipe such that cavitation will not occur.

Approach

Problem Description

Assume that points 1, 2 and 3 lie on a streamline, and Bernoulli's equation is applicable.

For constant diameter pipe, the velocity at points 2 and 3 is the same.

Cavitation occurs at a vapor pressure of p_{v} = 2.34 kPa (abs).

Assume the tank is large so that V_{1} = 0.

Assume the outlet of the pipe is acting like a free jet, i.e., p_{3} =
0.

Assume the density of water is 1000 kg/m^{3}.

Practice Homework and Test problems now available in the 'Eng Fluids' mobile app
Includes over 250 problems with complete detailed solutions.
Available now at the
Google Play Store and
Apple App Store.