FieldengFluid & Pressure
Pressure Drop per Unit Length
Friction pressure gradient for screening a measured pipe gradient.
Fluid & Pressure
Friction pressure gradient for screening a measured pipe gradient.
App id: FLUID-21. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
ΔP/L = (f/D) (ρ v² / 2)Inputs
| Name | Unit |
|---|---|
| Darcy friction factor | 1 |
| Inside diameter | mm |
| Density | kg/m3 |
| Mean velocity | m/s |
| Gravity (optional) | m/s2 |
Outputs
| Name | Unit |
|---|---|
| Pressure gradient (hero result) | Pa/m |
| Head loss per length | 1 |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Mean velocity < 0.3 | Low velocity | info |
Mean velocity > 5 | High velocity | caution |
Mean velocity > 3 | Elevated velocity | info |
Assumptions
- Head gradient is m of fluid per m of pipe (dimensionless slope).
Provenance
- Darcy–Weisbach written per unit length.