Hydraulic Head

08/11/25

“How can we conceptualize the total potential of a fluid’s pressure?”

We know that a fluid that is higher than another will usually flow downwards if they’re connected. However, if the lower fluid has a high enough pressure or velocity, then it can overpower the higher fluid and move upwards. One way to conceptualize this is to imagine that the pressure and kinetic energy of each fluid adds extra height, and whichever fluid has the highest theoretical “height” will govern the direction of flow. This is the concept behind Hydraulic Head, as illustrated by the equation h = P/(rho_w * g) + z + v^2/(2*g), where h is the hydraulic head, P the fluid pressure, rho_w the fluid density, g the gravitational constant, z the fluid elevation, and v the fluid velocity.