Fluid Mechanics
Pipe Flow Calculator
💧 Q = A · v
Calculate flow rate, velocity, and pressure drop in pipes.
Pipe Properties
Pipe Diameter
mm
Internal diameter of the pipe
Pipe Length
m
Length of the pipe
Roughness (ε)
mm
Pipe roughness (0.045mm for commercial steel)
Fluid Properties
Fluid
Select fluid or choose Custom for manual properties
Density (ρ)
kg/m³
Fluid density (Water: 1000 kg/m³)
Dynamic Viscosity (μ)
Pa·s
Viscosity (Water: 0.001 Pa·s at 20°C)
Flow
0
Flow Rate
0 m³/s
Q = A · v
Velocity
0 m/s
Cross-Sectional Area
0 m²
Reynolds Number
0
Pressure Drop
0 Pa
📊 Detailed Breakdown
| Parameter | Value | Unit |
|---|
How the formula works
Q = A · v | Re = ρ · v · D / μ | ΔP = f · (L/D) · (ρ · v²/2)
- Flow Rate (Q) = Cross-Sectional Area × Velocity
- Cross-Sectional Area (A) = π × (D/2)²
- Reynolds Number (Re) = ρ · v · D / μ (laminar: <2300, turbulent: >4000)
- Darcy Friction Factor (f) = Colebrook equation (iterative)
- Pressure Drop (ΔP) = f · (L/D) · (ρ · v²/2) (Darcy-Weisbach)
- Fluid properties: Water (ρ=1000, μ=0.001), Air (ρ=1.225, μ=0.000018), Oil (ρ=900, μ=0.05)
- Roughness: Commercial steel (0.045mm), PVC (0.0015mm), Cast iron (0.26mm)
- Enter velocity or let the calculator determine it from flow rate