# ThermalConductivity¶

Type: 2-Tensor, or section [v_1, …, v_9] -/- optional

Defines the thermal conductivity Units are Watt per meter kelvin,

A constant thermal conductivity can be defined by assigning a rank-2 tensor:

```Material {
# defines a constant thermal conductivity
ThermalConductivity =
[..., ..., ...
..., ..., ...
..., ..., ...]
}
```

Assign a scalar for an isotropic thermal conductivity .

For more general cases, the thermal conductivity may be given as a section in order to deal with space, time, and parameter dependent definitions:

```# define the thermal conductivity  as a section
ThermalConductivity {
Python {...}
...
}
```

Field definitions within the section `ThermalConductivity` are summed up. Consult the subsequent sections to see which types of field definitions are allowed.