Two free vortices of equal strength, but opposite direction of rotation, are superimposed with a uniform flow (v~ = uˆi). the first vortex, of clock-wise rotation, is located at (0,h) and the second is located at (0,-h). the stream function for a vortex of positive strength is given by

Water is siphoned from a large tank and discharges into the atmosphere through a 50-mm diameter tube. the end of the tube is b = 2.1 m below the tank bottom which is a = 7.4 m deep, and viscous effects are negligible. determine the maximum height h over which the water can be siphoned without cavitation occurring. atmospheric pressure is 101.4 kpa, and the water vapor pressure is 1.79 kpa (absolute)