### About

**Multi-layered wall**

The goal of this virtual lab is to illustrate the computation of the steady-state heat conduction in a three-layered wall. The steady-state heat conduction is assumed to be one-dimensional.

The wall is composed of three layers of different materials and thickness

*,*

**L**_{A}**an**

*L*_{ B}

**L**_{C}**. The temperature of the inner surface of the wall is**

*and the outside temperature*

**T**_{1}_{ }*(see figure 1).*

**T**_{4}

**q**_{x}**)and the temperature at the interfaces of the diferent layers**

**(**,

*T*_{ 2}**) are calculated.**

*T*_{3}Thermal conductivities of the layer's materials (

**k**_{A}**,**

**,**

*k*_{B}

**k**_{C}**) are assumed to be independent of others model variables. The thickness of the layer that compose the walls are model parameters. The wall surface (**

*) is assumed to be constant. The*

**S***parameter is not used in the model equations, because*

**S***doesn't depend on this parameter.*

**q**_{x}The mathematical model is described by the following equations:

*T*_{1}- T_{2}= (L_{a}/k_{a}) * q_{x}T_{2}- T_{3}= (L_{b}/k_{b}) * q_{x}T_{3}- T_{4 }= (L_{c}/k_{c}) * q_{x}Dpto. de Informática y Automática

E.T.S. de Ingeniería Informática, UNED

Juan del Rosal 16, 28040 Madrid, Spain

### For Teachers

### Translations

### Software Requirements

Android | iOS | Windows | MacOS | |

with best with | Chrome | Chrome | Chrome | Chrome |

support full-screen? | Yes. Chrome/Opera No. Firefox/ Samsung Internet | Not yet | Yes | Yes |

cannot work on | some mobile browser that don't understand JavaScript such as..... | cannot work on Internet Explorer 9 and below |

### Credits

Carla Martín; Tan Wei Chiong; Loo Kang Wee

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### Sample Learning Goals

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### For Teachers

Heat conducts through solids at different rates, and is dependent on the thickness of the solid and the heat conductivity of the solid.

We call this a steady-state conduction if the temperature difference driving the heat transfer is constant. In this simulation, it is assumed that the left side of a three-layered solid is set at a constant 25°C and the right side is set at a constant 0°C.

This simulation assumes that there is no loss of heat from the system (i.e.: this is a closed system). There are 3 walls in the graph on the left, representing 3 different solids that the heat conducts through. The graph on the right plots the temperature-thickness graph, showing how the temperature changes through the solids, and color-coded to represent the solid the heat travels through at that point.

There are 6 sliders to adjust the thickness and conductivity of each wall at the top of the simulation.

Research

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### Video

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### Version:

- http://weelookang.blogspot.com/2018/05/steady-state-heat-conduction-javascript.html
- http://www.euclides.dia.uned.es/simulab-pfp/curso_online/cap7_caseStudies/sec_heatWall.htm by Alfonso Urquia and Carla Martin-Villalba

### Other Resources

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