Calculator · Fluid Mechanics
Minor Loss Calculator
Fittings, bends, valves, entries and exits dissipate head locally. Each is described by a loss coefficient K ≥ 0 acting on the velocity head of the section the coefficient refers to.
Inputs
Group several fittings by adding their coefficients, as long as they all refer to the same section.
Only needed for the pressure-drop form.
Results
Minor head loss h_m = K V²/(2g)
A nonnegative magnitude, like every loss in this domain.
| Loss coefficient K | 2.5 |
|---|---|
| Mean speed V | 3 m/s |
| Fluid density ρ | 1000 kg/m³ |
| Minor head loss h_m | 1.1472 m |
| Pressure drop Δp_m = ρ g h_m | 11.25 kPa |
Explore in the Lab
The Lab adds the minor loss to the major loss of the same segment.
Technical reference
h_m = K V² / (2g)
Δp_m = ρ g h_m
V = Q / A
- h_m
- local (minor) head loss[m]
- K
- loss coefficient of the fitting, K ≥ 0[-]
- V
- mean speed of the reference section[m/s]
- ρ
- density of the fluid[kg/m³]
A negative K is not a valid loss model: a fitting cannot add energy to the flow.
A coefficient always refers to a stated section. Adding coefficients that refer to different diameters without converting them is a modelling error.
Reference case: K = 2.5 at V = 3 m/s gives h_m ≈ 1.1472 m.