AbraCalc

Reynolds Number: Water at 2 m/s in a 1 cm Diameter Tube

Water at 2 m/s through a 1 cm tube gives Re = 20000, clearly in the turbulent regime for pipe flow.

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How to use this tool

  1. Enter fluid density ρ, flow velocity v, characteristic length l and dynamic viscosity μ in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your reynolds number re and the full breakdown beneath it.

Determine whether flow is turbulent in a 1 cm diameter water tube by calculating the Reynolds number at 2 m/s velocity.

Frequently asked questions

What fluid properties should I use for water and air?
Water at 20°C: ρ = 998 kg/m³, μ = 0.001002 Pa·s. Air at 20°C: ρ = 1.204 kg/m³, μ = 1.81×10⁻⁵ Pa·s.
What is the characteristic length for a pipe?
For flow inside a pipe, use the internal diameter as the characteristic length. For flow over a flat plate, use the plate length.