Prandtl Number Calculator

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Calculate the Prandtl Number (Pr), a dimensionless number representing the ratio of momentum diffusivity to thermal diffusivity.

Fluid Material Properties

Dynamic Viscosity (μ) (Pa·s)

undefined (J/kg·K)

Thermal Conductivity (k) (W/m·K)

Calculation Results

Enter fluid properties

About this calculator

Overview

The Prandtl Number (Pr) is used in heat transfer and fluid dynamics. It helps determine if momentum or thermal energy diffuses faster through a fluid.

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Pro Tips

Pr = (Viscosity × Specific Heat) / Thermal Conductivity.
Pr << 1 (e.g., liquid metals) means heat diffuses much faster than momentum.
Pr >> 1 (e.g., oils) means momentum diffuses much faster than heat.

Fun Facts

"For air at room temperature, Pr is about 0.7."
"For water at 20°C, Pr is about 7.0."
"Ludwig Prandtl was an influential German physicist who also developed the boundary layer concept."

Formula: Pr = (μ · cp) / k