Energy equation and continuity equation mismatch

Thread starter nirmaljoshi
Start date Jul 1, 2015
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Continuity Continuity equation Energy

AI Thread Summary

The discussion centers on the discharge from a pipe at a height of 100 meters to the atmosphere, with an inlet discharge of 0.4 m³/s. Using Bernoulli's equation, the velocity is calculated to be approximately 44 m/s, assuming no losses. In contrast, applying the continuity equation with a pipe diameter of 0.3 meters yields a velocity of about 5.65 m/s. The key question arises regarding the accuracy of these calculations and whether the open end of the pipe is indeed 100 meters above ground. The conversation highlights the importance of understanding fluid dynamics principles to resolve the discrepancies in velocity calculations.

Jul 1, 2015

nirmaljoshi

A pipe is discharging from H=100m to an open atmosphere. The available discharge at inlet is 0.4m3/s

1. The bernauli's equation tells v=sqrt(2*g*H), neglecting any losses in the pipe, v=~44m/s
2. continuity equation tells v=Q/A, say diameter of pipe=0.3m, v=~5.65m/s

which is correct?

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Jul 2, 2015

russ_watters

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Are you saying the open end of the pipe is 100m above ground?

Which do you think is correct and why?

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