Cooling

Reynolds Number – Cooling Water

Calculate Reynolds number for water flowing through circular mold cooling channels.

Cooling circuit

Enter a channel diameter greater than 0.
Internal diameter of the circular cooling channel.
Flow rate cannot be negative.
Use the flow rate through the circuit being evaluated, not the total manifold flow.
°C
Enter a water temperature between 0 and 100 °C.
Water density and dynamic viscosity are estimated automatically from temperature.
Water properties used
Density
Dynamic viscosity

Live results

Average water velocity
Reynolds number
Waiting for input

Enter valid values to evaluate the flow regime.

How this calculation works

Flow rate → Area → Velocity → Water properties → Reynolds → Flow regime

1. Convert the flow rate

2. Calculate channel area

\[A=\frac{\pi D^2}{4}\]

3. Calculate average water velocity

\[v=\frac{Q}{A}\]

4. Calculate Reynolds number

\[Re=\frac{\rho vD}{\mu}\]

5. Interpret the flow regime

  • Laminar: Re < 2300
  • Transitional: 2300 ≤ Re ≤ 4000
  • Turbulent: Re > 4000
Turbulent flow generally improves convective heat transfer in cooling channels, but increasing flow also increases pressure loss and pumping demand.