Question

The hydraulic grade line is the velocity head below the energy

Answer 1

Answer:

Explanation:

Just assume those lines are simple graphical representation of how the flow energy behaves along a direction. The rough idea that lies behind flow energy is unless a flow is inviscid (zero viscosity), the whole amount of available energy will decrease because of friction. Friction create head losses, thus energy decrease.

For practical purposes, I will assume energy is expressed in terms of head, expressed in meters. The total energy available in a flow, at a specific position, noted H can be written as follows :

H=Pρg+z+V22g

As you can see, this total energy head is a sum of three energy heads :

A pressur...

Answer 2

The Hydraulic Grade Line (HGL) lies one velocity head below the the Energy Grade Line (EGL) In case the cross section is constant along the streamline and the flow steady, discharge remains constant and also so does velocity. Therefore, velocity head remains the same aswell.