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Straight Fin Thermal Efficiency & Heat Dissipation Calculator

Extended cooling fins enhance convective heat rejection from hot electronic microprocessors, heat sinks, and motorcycle engine cylinders.

Protrusion height of fin from heat source base.

Thickness of individual fin profile.

Depth of fin along the base plate.

Material thermal conductivity (205 for 6061 aluminum, 385 for copper).

Air convection coefficient (5-25 natural convection, 30-100 forced air).

Hot base attachment temperature.

Cooling ambient fluid temperature.

Calculated Result
14.43 W

Heat Dissipation Rate (q_fin)

Heat Dissipated

14.43 W

Fin Efficiency (η_f)

91.4%

Fin Effectiveness (ε)

37.5:1 (Justified fin add)

Fin Parameter (m)

13.07 m⁻¹

Corrected Length (L_c)

41 mm

Ideal Isothermal Heat

15.79 W

Calculation Breakdown

  1. Fin Parameter & Harper-Brown Corrected Lengthm = √(2 × 35 / (205 × 0.002)) = 13.07 m⁻¹, L_c = 40 + 2/2 = 41 mm
  2. Fin Thermal Efficiencyη_f = tanh(m × L_c) / (m × L_c) = tanh(0.536) / 0.536 = 91.4%
  3. Actual Convective Heat Dissipationq = η_f × (2 × w × L_c × h × ΔT) = 0.914 × 15.79 W = 14.43 W

Fin Thermal Performance

Interactive visualization based on your current inputs

Value
0.023466992Heat Rejection (W)Efficiency (%)Effectiveness (x)Param m (m⁻¹)ParameterValue

What Is the Straight Fin Thermal Efficiency & Heat Dissipation Calculator?

The Straight Fin Thermal Efficiency Calculator sizes extruded cooling fins and heat sinks for electronics and thermal machinery.

How Does the Straight Fin Thermal Efficiency & Heat Dissipation Calculator Work?

It solves the classical 1D fin differential equation with a convective tip boundary condition using Harper-Brown length correction.

Straight Fin Thermal Efficiency & Heat Dissipation Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

m = \sqrt{\frac{2h}{k t}}, \quad \eta_f = \frac{\tanh(m L_c)}{m L_c}, \quad q = \eta_f \cdot (2 w L_c h \Delta T)

1D Fourier conduction and Newton cooling energy balance for extended rectangular surfaces.

How to Use the Straight Fin Thermal Efficiency & Heat Dissipation Calculator

  1. Input fin length, thickness, and width in mm.
  2. Specify metal thermal conductivity (aluminum or copper).
  3. Enter convective heat transfer coefficient (h) and temperature boundary conditions.

Step-by-Step Example Calculation

Aluminum Heat Sink Extruded Fin

Input Values:

finLengthMm:40
finThicknessMm:2
finWidthMm:100
thermalConductivityK:205
heatTransferCoeffH:35
baseTempC:80
ambientTempC:25
Worked Steps: Fin parameter m = 13.07 m⁻¹, efficiency is 91.5%, and heat dissipation is 14.45 W per fin (effectiveness: 37.5x).

Understanding Your Result

Fin Efficiency (ηf): Ratio of actual heat dissipated to ideal heat if the entire fin were at base temperature.

Heat Dissipated: Total convective heat rejection in Watts.

Fin Effectiveness (ε): Heat dissipation increase compared to bare unfinned base area.

Factors That Affect the Result

  • Higher material thermal conductivity maintains higher tip temperatures, boosting efficiency.

When Should You Use This Calculator?

  • CPU and GPU heat sink design, power transistor thermal management, transformer radiator fins, and compressor air coolers.

Assumptions & Limitations

  • Assumes steady-state 1D heat conduction along fin length and uniform convection coefficient.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard heat transfer formulation per Incropera & Dewitt.

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