# Lump Mass model – steady state

In this calculator you can calculate the steady state
temperatures of a network of bodies. Follow the steps, and if you are
ready press the button calculate and evaluate the results in the graph.

In a lumped capacity model, a thermal system is divided in to

• Heat Capacities
• Thermal Couplings

The heat capacities are called Nodes, and it is assumed that the temperature in one node is uniform. Heat capacities can be:

• Large parts
• Thermally conductive parts
• Multiple parts with good thermal conducion between them
• Parts with "important" temperatures

In the image above, a three node system is shown. Part 1 is in contact with body 2 by a few connection points. Body 2 is in contact with body 3, which is a large and surrounds the other parts.
In the picture to the right, the conductive couplings and radiation couplings identified. Body 1 has a heat source.

Use the calculation tool to calculate the temperatures.

### Step 1 Input system size

 #nodes 2 3 4 5 6 How many nodes does the system contain?(2-6)if you change this, all data will be lost.

### Step 2 Input thermal couplings

 from to type value[W/K] node1 node2 node3 node4 node5 node6 node1 node2 node3 node4 node5 node6 Conduction Convection Radiation

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### Step 3 Constant temperatures nodes (e.g. heatsinks)

 node temperature [K] node1 node2 node3 node4 node5 node6 -

### Step 4 Input Heat loads

 node Power [W] node1 node2 node3 node4 node5 node6 -

### Step 5 Calculate

Press calculate to evaluate the results

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(drag blocks to rearrange locations)

This calculator was made for educational purposes only. No rights can be obtained from the results you calculate. If you have comments please contact info@dspe.nl.