Chapter 1 – Wave Plan Method
Surge Analysis and the Wave Plan Method
Supplementary Material: Example Problems and Solutions
Chapter 1 – Problem 1.17
1.17 Consider two pipe elements having the same internal diameters of 1000 mm and the same celerity values of 500 m/s which are connected by a closed gate valve as shown in the following.

a. If a pressure wave of -50m approaches the closed valve from the Pipe-2 side and another pressure wave of 100m approaches the closed valve from the Pipe-1 side (both waves arriving at the valve at the same time), what are the magnitude and sign of the associated reflected and transmitted pressure waves? [Answers: The reflected and transmitted waves on the Pipe-2 side are -50m and 0, respectively. The reflected and transmitted waves on the Pipe-1 side are +100m and 0, respectively.]
b. If the pressure head at the Pipe-2 side of the closed valve prior to the wave impingement is 100m, what is the pressure head at that location after the wave reflection? [Answer: 0]
c. If the pressure head at the Pipe-2 side of the closed valve prior to the wave action is 91m, what is the pressure head at that location after the wave action? [Answer: -9m, slightly above the cavitation head for water]
d. If the pressure head at the Pipe-2 side of the closed valve prior to the wave action is 89m, what is the pressure head at that location after the wave action? [Answer: -11m, slightly below the cavitation head for water]
e. What would be the reflected and transmitted pressure waves, if the pipes connect a full-bore gate valve which is fully open and offers zero resistance to flow?
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