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Cooling Circuit Reynolds Number

Calculate Reynolds number and coolant velocity for one circular cooling circuit at its operating conditions.

Example starting values are prefilled to demonstrate the calculation. Replace them with your measured, quoted, or job-specific inputs before relying on a result.

Inputs

Inputs

Range: at least 0.0 US gal/min

Enter measured or design flow through one circuit, not total manifold flow unless that total passes through this one channel.

Range: at least 0.0 in

Use the actual channel inside diameter in inches. For noncircular passages, use a justified hydraulic diameter rather than an arbitrary nominal size.

Range: at least 0.0 cSt

Use coolant kinematic viscosity at the circuit operating temperature and for the actual water/glycol mixture. Supplier data may be reported in mm²/s; 1 mm²/s = 1 cSt.

Result

Channel cross-sectional area (in^2)
0.19635
Cooling Circuit Reynolds Number (dimensionless)
6,299.913
Calculated coolant velocity (ft/s)
1.634
Interpretation and limits
This is the dimensionless Reynolds number for one circular circuit using the entered flow, inside diameter, and temperature-specific kinematic viscosity. It does not select a universal flow-regime boundary or prove adequate heat transfer; assess circuit geometry, coolant properties, pressure drop, and process performance separately.

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