Extended Surface (Fin) Calculator

For straight rectangular fins with an insulated tip.

General Parameters

Fin Geometry

Fin Array

Results

Fin Parameter (m): — 1/m

Fin Efficiency ($\eta_f$): —

Heat Transfer per Fin ($q_f$): — W

Total Heat Transfer ($Q_{total}$): — W

Notes & Formulas (Rectangular Fin, Insulated Tip)

The following calculations assume a straight rectangular fin with an adiabatic (insulated) tip.

  • Perimeter ($P$): $P = 2(w+t)$
  • Cross-sectional Area ($A_c$): $A_c = w \cdot t$
  • Fin Parameter ($m$): $m = \sqrt{\frac{hP}{kA_c}}$
  • Fin Efficiency ($\eta_f$): $\eta_f = \frac{\tanh(mL)}{mL}$ (If $mL=0$, $\eta_f=1$)
  • Heat Transfer from a single fin ($q_f$): $q_f = \sqrt{hPkA_c}(T_b – T_\infty)\tanh(mL)$
  • Total Heat Transfer ($Q_{total}$): $Q_{total} = N \cdot q_f$

  • $L$: Fin Length
  • $t$: Fin Thickness
  • $w$: Fin Width
  • $h$: Convective Heat Transfer Coefficient
  • $k$: Thermal Conductivity of Fin Material
  • $T_b$: Base Temperature
  • $T_\infty$: Ambient Fluid Temperature
  • $N$: Number of Fins