Forced convection heat sink

	Forced Convection Heat Sink
Online calculator for forced convection heat sinks with isothermal bottom plates in confined flow, (no bypass). A more elaborate procedure can be found in the Hsink code. It can in addition handle discrete heat sources, bypass flow and flow channels with fans. See examples Related links Straight fins are better than pin fins! Thermal design for electronics Thermal online tools Unit conversion Comments Your need to install a Java console to display this applet. All modern browsers have this option. General The procedure is based on the equations in chapter 17 of the theory document. To fully enjoy all features, look at the editing options. Inputs Air temp The temperature of the incoming air. Length The length of the heat sink in the flow direction. Width The width of the heat sink perpendicular to the flow direction. Fin count The fin count. The outer side of the two extreme fins do not contribute to the heat dissipation. Fin height The distance from the bottom plate to the top of the fins. Fin thickness The thickness of the fins. Conductivity The thermal conductivity of the fin material. The table below shows this value for some common materials. Extruded aluminium 210 W/mK Cast-aluminium 150 W/mK Copper 390 W/mK For other materials see: Tools from Maya Thermal efficiency Is defined as the ratio of the air temperature increase and the inlet temperature difference. 100% signifies that the exit air has the same temperature as the bottom plate. Analogy number Is a measure of how efficient the pressure losses are used for heat dissipation. This concept is discussed in the article Heat Sinks and Reynolds Analogy. Fin efficiency Is defined as the ratio of the average fin-to-air temperature difference and the virtual fin-to-air temperature difference for infinite thermal conductivity. Heat diss The heat dissipated. The bottom plate is assumed isothermal. Start and end velocity> The air velocity is defined as the average velocity in the cross section in front of the fins. (Marked with red in the 2-D view). The calculation is made in 30 steps between the start and end velocities. Pressure and altitude These two inputs are mutually inter-dependent. On cursor exit from one, the other is updated. The allowed altitude range is 0 - 11000 m. Editing options Save last/Delete last buttons Saves or deletes the last curve. Maximum capacity is 5 curves. Save/read data button Opens an panel with an XML text that can be used to save and read input data. Tabulated results Clicking in the diagram opens a panel with tabled results that can be copied and pasted into a spread sheet program. 3D adjustment The 3D view is adjusted by dragging the mouse in the image. The left button controls X and Y-axis rotation. The right button controls Z-axis rotation and view distance. Discrete heat sources If there are discrete heat sources, the problem can be solved by combining with the applet implementation in Convection Cooled Plate with Sources. Top of page

Forced Convection Heat Sink

Online calculator for forced convection heat sinks with isothermal bottom plates in confined flow, (no bypass).

A more elaborate procedure can be found in the Hsink code.
It can in addition handle discrete heat sources, bypass flow and flow channels with fans.
See examples

General

The procedure is based on the equations in chapter 17 of the theory document.
To fully enjoy all features, look at the editing options.

Inputs

Air temp
The temperature of the incoming air.

Length
The length of the heat sink in the flow direction.

Width
The width of the heat sink perpendicular to the flow direction.

Fin count
The fin count. The outer side of the two extreme fins do not contribute to the heat dissipation.

Fin height
The distance from the bottom plate to the top of the fins.

Fin thickness
The thickness of the fins.

Conductivity
The thermal conductivity of the fin material. The table below shows this value for some common materials.
Extruded aluminium 210 W/mK
Cast-aluminium 150 W/mK
Copper 390 W/mK
For other materials see: Tools from Maya

Thermal efficiency
Is defined as the ratio of the air temperature increase and the inlet temperature difference. 100% signifies that the exit air has the same temperature as the bottom plate.

Analogy number
Is a measure of how efficient the pressure losses are used for heat dissipation. This concept is discussed in the article Heat Sinks and Reynolds Analogy.

Fin efficiency
Is defined as the ratio of the average fin-to-air temperature difference and the virtual fin-to-air temperature difference for infinite thermal conductivity.

Heat diss
The heat dissipated. The bottom plate is assumed isothermal.

Start and end velocity>
The air velocity is defined as the average velocity in the cross section in front of the fins. (Marked with red in the 2-D view). The calculation is made in 30 steps between the start and end velocities.

Pressure and altitude
These two inputs are mutually inter-dependent. On cursor exit from one, the other is updated. The allowed altitude range is 0 - 11000 m.

Editing options

Save last/Delete last buttons
Saves or deletes the last curve. Maximum capacity is 5 curves.

Save/read data button
Opens an panel with an XML text that can be used to save and read input data.

Tabulated results
Clicking in the diagram opens a panel with tabled results that can be copied and pasted into a spread sheet program.

3D adjustment
The 3D view is adjusted by dragging the mouse in the image. The left button controls X and Y-axis rotation. The right button controls Z-axis rotation and view distance.

Discrete heat sources
If there are discrete heat sources, the problem can be solved by combining with the applet implementation in Convection Cooled Plate with Sources.

Top of page