Online thermal calculator for wall-to-wall characteristics in a rectangular enclosure filled with air. For the horizontal case it is assumed that the bottom side has the highest temperature.


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Your need to install a Java console to display this applet. All modern browsers have this option.

General

Three 3 flow regions are covered: still air, laminar and turbulent flow. The transitions are difficult to express mathematically. The curves are therefore somewhat jumpy.


Inputs

Side 1
For the vertical case it is the height. For the horizontal case it is one of the sides.

Side 2
For the vertical case it is the width. For the horizontal case it is one of the sides.

Gap start
The lowest wall-to-wall distance to calculate.

Gap end
The highest wall-to-wall distance to calculate

Air temp
The temperature for the side with the lowest temperature.

Temp diff
The temperature difference between the sides.

Heat diss
The dissipated heat.

Orientation
The orientation can be vertical or horizontal. In the former case it is assumed that the heat flow is directed upwards.

Include radiation
If checked radiation is included. The emissivity is set to 0.9 for both sides.


Edit option

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

Note

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

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