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The primary purpose of this study is to explore
experimentally thephenomenon of liquid column separation
which may occur within a pipewaterhammer propagation, and
to explore further the causes of this phenomenonand its effects
on the pipe transient.
For different closure times of avalve, the shorter the duration
ofthe valve,the easier the liquid column separation is to be
found. Besides, the initial flow to be closed condition is
oneimportant factor to have liquid column separation. A high
initial flow rate causes the liquid column separated easily
because of its great change in velocity; on the other hand, a
high initial pressure is hard to form liquid column separation
in the pipe. Liquid column separates as
the liquid pressure in the pipe gets lower than its vaporizing
pressure. This phenomenon slows down thepropagating velocity of
waterhammer. The study employs the technique of spectrum and co-
relation analyse to first present calculate the velocity of a
waterhammer wave without the liquid column separation, and then
to analyze the condition with it. Under the coupled influence of
liquid and vapor, the propagation of waterhammer can''t get to a
constant speed in a pipe. This difficulty makes the present
study to perform qualitative discussion on the trend of
velocityvariation and the celerity of waterhammer without liquid
column separation. Finally, this thesis suggests the further
study as well.
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