Fluid Dynamics question Grade lines present important data t

Fluid Dynamics question

Grade lines present important data to engineers who work with designing fluid systems. Consider the energy grade lines and hydraulic grade lines – what differs between them? In detail, list three situations where there might be a difference between the two?

Solution

>> The hydraulic grade and the energy line are graphical presentations of the Bernoulli equation

>> The energy of a real fluid decreases as it moves through a pipe. The energy budget in a pipeline system is materialized by the energy grade line. The hydraulic grade line is lower than the energy line by the velocity head.

>> EGL shows the height of the total Bernoulli constant while HGL is the height to which liquid would rise in a piezometric tube attached to the pipe. HGL is obtai ed as EGL minus the velocity head Vg²/2 . The fall of the EGL reflects the energy losses in the system. EGL drops slowly due to friction losses and it drops sharply due to a major loss (a valve or transition) or due to work extraction (to a turbine). The EGL can rise only if there is work addition (as from a pump).