Darcy-Weisbach Pressure Drop

Fluid & Pressure

Straight-pipe friction pressure drop from a known Darcy friction factor.

App id: FLUID-05. 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 = f (L/D) (ρ v² / 2)

Inputs

Name	Unit
Darcy friction factor	`1`
Pipe length	`m`
Inside diameter	`mm`
Density	`kg/m3`
Mean velocity	`m/s`
Gravity (optional)	`m/s2`

Outputs

Name	Unit
Pressure drop (hero result)	`kPa`
Head loss	`m`

Diagnose

This tool does not attach diagnose observations.

Assumptions

Fully developed flow in a constant-diameter circular pipe.
Leave gravity blank for 9.80665 m/s².

Provenance

Darcy–Weisbach equation. f is the Darcy factor, not Fanning.