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Prandtl Number

Compare momentum diffusivity against thermal diffusivity.

visual calculatorDimensionless Numbers

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

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Prandtlheat transferconvection
formula
KaTeX rendered
Pr = mu Cp / k = nu / alpha\begin{aligned}\text{Pr = mu Cp / k = nu / alpha}\end{aligned}
ASCII sourcePr = mu Cp / k = nu / alpha
Pr = μCₚ / k
0.712
fluid type
Air-like gases

Pr ≪ 1: thermal diffusivity dominates (liquid metals). Pr ≈ 1: air. Pr ≫ 1: viscosity dominates (oils).