\[v=\frac{Q}{A}\]
Variables
vaverage fluid velocity (m/s)
Qvolumetric flow rate (m³/s)
Aflow cross-sectional area (m²)
Description
What is this formula?
The pipe velocity equation calculates the average velocity of a fluid flowing through a pipe from the volumetric flow rate and the pipe cross-sectional area.
When to use it
Use this formula when sizing irrigation pipes, checking allowable flow velocities, estimating erosion risks, or evaluating pumping system performance.
Example
An irrigation pipeline carries:
Q = 0.020 m³/s
The pipe internal diameter is:
D = 0.15 m
Cross-sectional area:
A = πD²/4
A = π × 0.15² / 4
A = 0.01767 m²
Formula:
v = Q/A
Substitution:
v = 0.020 / 0.01767
v = 1.13 m/s
Result:
The average water velocity in the pipe is approximately 1.13 m/s.
Applications
- Irrigation pipe design
- Pumping systems
- Water distribution networks
- Flow velocity verification
- Hydraulic performance analysis