> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Thermal Bonded Contact

<CardGroup cols={2}>
  <Card title="Boundary, Boundary, Scalar Field, Scalar" href="#boundary-boundary-scalar-field-scalar" />

  <Card title="CAD Face, CAD Face, Scalar Field, Scalar" href="#cad-face-cad-face-scalar-field-scalar" />
</CardGroup>

***

## About this Block

**What it does:** This block creates a bonded contact between two FE boundaries, allowing for heat flux between the two components.

**Common uses:**

* Domains of two regions do not necessarily share common nodes and element faces; it is necessary to "tie" these two regions together mathematically and couple them mechanically.

**Tips:**

* Contact resistance can be defined to account for thin membrane material at the boundary, such as thermal paste.
* The thermal contact resistance between two materials is often calculated from experimental tests of contact conductance, and the values can be found in thermal conductivity tables.
* If boundary entities can't be found within the defined tolerance, try refining the FE Mesh or increasing the tolerance to effectively capture the connection between the two boundaries

## Example File

Download Example: [Thermal Contact](https://storage.googleapis.com/files-learn/static/ExtendedBlockDocs/thermal_bonded_contact.ntop)
![Example Screenshot](https://storage.googleapis.com/files-learn/static/ExtendedBlockDocs/Thermal_Bonded_Contact.png)

***

<h2 id="boundary-boundary-scalar-field-scalar">
  Boundary, Boundary, Scalar Field, Scalar
</h2>

Creates a bonded contact between two boundaries which allows for heat flux between the two domains. A contact resistance can be defined to account for thin membrane material at the boundary such as thermal paste.

### Inputs

| Name        | Type                                                               | Description                                                                                                                                                                                  |
| ----------- | ------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Independent | [Boundary](../../../../block-documentation/types/boundary)         | The independent boundary.                                                                                                                                                                    |
| Dependent   | [Boundary](../../../../block-documentation/types/boundary)         | The dependent boundary.                                                                                                                                                                      |
| Resistance  | [Scalar Field](../../../../block-documentation/types/scalar-field) | Thermal resistance of the contact elements.                                                                                                                                                  |
| Radius      | [Scalar](../../../../block-documentation/types/scalar)             | Positional tolerance for dependent boundary relative to the independent boundary. Nodes in the dependent boundary beyond this tolerance will not be constrained to the independent boundary. |

### Outputs

| Type                                                         |
| ------------------------------------------------------------ |
| [Connector](../../../../block-documentation/types/connector) |

***

<h2 id="cad-face-cad-face-scalar-field-scalar">
  CAD Face, CAD Face, Scalar Field, Scalar
</h2>

Creates a bonded contact between two CAD faces which allows for heat flux between the two domains. A contact resistance can be defined to account for thin membrane material at the boundary such as thermal paste.

### Inputs

| Name        | Type                                                               | Description                                                                                                                                                                                  |
| ----------- | ------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Independent | [CAD Face](../../../../block-documentation/types/cad-face)         | The CAD face defining the independent boundary.                                                                                                                                              |
| Dependent   | [CAD Face](../../../../block-documentation/types/cad-face)         | The CAD face defining the dependent boundary.                                                                                                                                                |
| Resistance  | [Scalar Field](../../../../block-documentation/types/scalar-field) | Thermal resistance of the contact elements.                                                                                                                                                  |
| Radius      | [Scalar](../../../../block-documentation/types/scalar)             | Positional tolerance for dependent boundary relative to the independent boundary. Nodes in the dependent boundary beyond this tolerance will not be constrained to the independent boundary. |

### Outputs

| Type                                                         |
| ------------------------------------------------------------ |
| [Connector](../../../../block-documentation/types/connector) |