Pipe Heat-Transfer Designer

Compute internal-flow Nusselt number, h, and total heat rate with Dittus-Boelter/Gnielinski correlations and a pipe sketch.

visual calculatorHeat Transfer

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.

input scale

model

check

Nusseltpipe heat transferGnielinskiconvection

formula

KaTeX rendered

\begin{aligned}\text{Nu\_Gn = (f/8)(Re-1000)Pr / [1 + 12.7(f/8)\^{}(1/2)(Pr\^{}(2/3)-1)]}\end{aligned}

ASCII source

Nu_Gn = (f/8)(Re-1000)Pr / [1 + 12.7(f/8)^(1/2)(Pr^(2/3)-1)]

Re_DPrfluid k (W/m/K)pipe D (m)heated length (m)wall-bulk DeltaT (K)

Nu Dittus-Boelter

271.36

Nu Gnielinski

308.25

h (W/m2/K)

7644.63

area (m2)

0.236

Q (W)

4.503e+4

turbulent correlation range. Use as a fast CFD wall heat-flux sanity check before committing to a conjugate heat-transfer mesh.

Nusselt pipe heat transfer Gnielinski convection