Reynolds Number Calculator

Reynolds Number Calculator

This calculator helps you determine the Reynolds number for fluid flow in a pipe or channel. The Reynolds number predicts the flow pattern of a fluid, such as whether the flow is laminar, turbulent, or transitional.

Formula:

\[ Re = \frac{\rho \cdot v \cdot D}{\mu} \] Where:

• \( Re \) = Reynolds number (dimensionless)
• \( \rho \) = fluid density (kg/m³ or slug/ft³)
• \( v \) = fluid velocity (m/s or ft/s)
• \( D \) = characteristic length (m or ft)
• \( \mu \) = dynamic viscosity (Pa·s or slug/ft·s)

Fluid Density (ρ): kg/m³slug/ft³

Fluid Velocity (v): m/sft/s

Characteristic Length (D): mft

Dynamic Viscosity (μ): Pa·sslug/ft·s

Calculate Reynolds Number

Result:

Key Features of the Formula

• Dimensionless Value: The Reynolds number is a dimensionless value that helps predict whether fluid flow will be laminar, turbulent, or transitional.
• SI and Imperial Units Supported: The calculator supports fluid density, velocity, diameter, and viscosity in both SI (metric) and Imperial units, automatically converting them for the calculation.
• Flow Pattern Determination: A low Reynolds number (Re < 2000) typically indicates laminar flow, while a high Reynolds number (Re > 4000) indicates turbulent flow. Transitional flow occurs between these values.
• Applications in Engineering: The Reynolds number is widely used in engineering fields such as fluid mechanics, aerodynamics, and chemical engineering to model fluid behavior in pipes, channels, and around objects.