Hodetap

Hodetap, in Norwegian technical usage, refers to the loss of hydraulic head in a fluid system. The term is formed from hodet (head) and tap (loss) and is commonly used in fluid mechanics, hydraulics, and piping design. It describes the decrease in the energy available to the fluid as it moves from one point to another due to friction, turbulence, and fittings.

Hydraulic head is a measure of potential energy per unit weight of the fluid and is typically expressed in meters of fluid. Head loss is the difference between heads at two sections of the system. The total head loss is the sum of major losses from pipe friction and minor losses from fittings, valves, and bends.

In engineering practice, head loss is calculated with the Darcy–Weisbach equation for major losses: h_f = f (L/D) (v^2/(2g)). Minor losses are represented as h_L = Σ K_i (v^2/(2g)). The overall head loss is h_L = h_f + Σ h_Li, and the corresponding pressure drop is Δp = ρ g h_L.

Applications include design and analysis of water distribution networks, building plumbing, irrigation systems, and heating, ventilation, and air conditioning piping. It informs pump selection and energy efficiency by predicting flow rates and pressure requirements.

Etymology and usage: Hodetap is primarily used in Norwegian engineering literature to translate “head loss.” Outside technical contexts, the term may appear as a literal compound of “head” and “loss” but is not a general medical or everyday term.