Page 118 - ebook fluid mechanics_finalize
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FLUID MECHANICS
When,
v1 = velocity in the smaller pipe upstream of the enlargement
v2 = velocity in the larger pipe
If hL = head lost at the enlargement, then by Bernoulli’s theorem,
p 1 v 1 2 p 2 v 2 2
+ = + + h L
2 g 2 g
Special case: When a pipe discharges into a large reservoir through a sharp exit,
conditions are equivalent to a sudden enlargement (refer Figure 5.3).
v1 = pipe velocity = v
v2 = reservoir velocity = 0
Figure 5.3 : Large Reservoir To A Sudden Enlargement
v 2
Loss of head at sharp exit into reservoir, hL = 2 g
If the exit is rounded, this loss is greatly reduced and is usually negligible.
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