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Friction Factor Calculator

Calculate Bernoulli energy conservation, Reynolds number (Re), Darcy-Weisbach head loss, hydrostatic pressure, and flow rates for friction factor.

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Input Fluid Parameters

Enter flow velocity, fluid density, pipe diameter, or viscosity.

Calculated Volumetric Flow Rate (Q)

0.0196 m³/s (19.6 L/s)
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Reynolds Number Regime

Re = (ρ × v × D) / μ. Flow is Laminar if Re < 2,300, Transient if 2,300 < Re < 4,000, and fully Turbulent if Re > 4,000.

Calculation Methodology & Details

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Formula

Bernoulli Equation: P₁ + ½ρv₁² + ρgz₁ = P₂ + ½ρv₂² + ρgz₂ Volumetric Flow: Q = A × v = (π/4) × D² × v Darcy-Weisbach Loss: h_f = f × (L/D) × (v² / [2g]) Hydrostatic Pressure: P = ρ × g × h

Applies continuum fluid dynamics, Navier-Stokes momentum equations, Archimedes' buoyancy principle, and Poiseuille viscous pipe flow.

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Important Disclaimer

Calculations assume incompressible Newtonian fluids under steady-state conditions unless Mach number compressible shock equations are selected.

How to Calculate Step-by-Step

Follow these steps to complete the calculation:

1

Step 1

Enter fluid density ρ (Water ρ=1000 kg/m³, Air ρ=1.225 kg/m³) or dynamic viscosity μ (Pa·s).

2

Step 2

Specify flow velocity v (m/s), pipe length L and diameter D, or submerged depth h (meters).

3

Step 3

View volumetric flow Q (L/s or GPM), Reynolds number Re, friction head loss h_f (meters), or hydrostatic pressure in kPa/PSI.

Detailed Insights & Expert Guide

ℹ️ About this Calculation

The Friction Factor Calculator calculates Bernoulli pressure heads, Reynolds number flow regimes, Darcy-Weisbach friction losses, Archimedes buoyancy forces, Venturi meter flow rates, and hydraulic pump power efficiency.

Variable Glossary

Input

Flow Rate (Q)

Volume of fluid passing through a pipe cross-section per unit time (m³/s or GPM).

Parameter

Hydrostatic Pressure

Pressure exerted by a fluid at equilibrium due to force of gravity: P = ρ × g × h.

FAQ

How does Archimedes' Principle determine buoyant force?
Archimedes' Principle states that any body completely or partially submerged in a fluid is buoyed up by a force equal to the weight of fluid displaced by the body: F_buoyant = ρ_fluid × V_displaced × g.
What is the Venturi Effect?
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (choke) of a pipe. Speed increases in the constriction, creating a measurable pressure drop used in flow meters and carburetors.
What is pump cavitation?
Cavitation occurs when local static pressure inside a pump impeller drops below the liquid's vapor pressure, forming vapor bubbles that violently collapse in high pressure regions, damaging pump blades.