In a flow-measuring device, what is velocity head?
Velocity head represents the elevation needed for fluid to reach the velocity V during frictionless free fall. It is a fundamental concept of fluid mechanics representing the bulk motion, i.e. the fluid’s kinetic energy. It can also be transformed into the pressure that the fluid would obtain where it is to be held without any energy loss.
It is measured as
Velocity head = V2/2g m
v = velocity of fluid
g = acceleration due to gravity;
From the expression, it is clear that it is that height that is required to attain a velocity v in under free fall.