What term is used to describe the sum of the friction head, the velocity head, and the pressure heads?

The correct term for the sum of the friction head, the velocity head, and the pressure heads is "Dynamic head." This term is used in fluid mechanics and hydraulics to describe the energy associated with a fluid in motion, which includes the kinetic energy (velocity head) and the potential energy due to pressure (pressure head), as well as the losses due to friction.

Dynamic head represents the total energy available in a fluid system for overcoming resistance and maintaining flow, taking into account not only the pressure and velocity of the fluid but also the energy lost due to friction along the flow path. Understanding this concept is crucial for effectively designing and analyzing fluid systems, ensuring that systems can deliver the required flow rates while minimizing energy losses.

Static head, on the other hand, refers only to the height of a fluid column when at rest, rather than considering fluid motion. Hydraulic head is often used synonymously with static head but can also include pressure head, without the dynamic aspect. Effective head typically pertains to specific applications or conditions and does not encompass the full sum of energetic terms in the context of flow dynamics as dynamic head does.