Kolmogorov Microscales

Compute the dissipative end scales of the turbulence cascade.

visual calculatorTurbulence & Wall Modeling

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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KolmogorovturbulenceDNS

formula

KaTeX rendered

\begin{aligned}\text{eta = (nu\^{}3 / epsilon)\^{}(1/4)}\\[0.35em]\text{tau\_eta = (nu / epsilon)\^{}(1/2)}\end{aligned}

ASCII source

eta = (nu^3 / epsilon)^(1/4), tau_eta = (nu / epsilon)^(1/2)

ν — kinematic viscosity (m²/s)ε — dissipation rate (m²/s³)L — integral length scale (m)U — velocity scale (m/s)

η (length)

4.29e-4m

τ_η (time)

0.0122s

u_η (velocity)

0.0350m/s

Re_L (large-scale)

6.67e+5

Re_η (Kolmogorov Re)

1.00

η ≈ (ν³/ε)^(1/4) · Re_η = u_ηη/ν ≈ 1 by definition. DNS needs Δx ≈ η.

Kolmogorov turbulence DNS