---
tags:
  - Academic
catalog:
  name: COMSOL Multiphysics
  description: General-purpose simulation software
  license_type: Academic
  disciplines:
    - Computational Engineering
  available_on:
    - web_interfaces:
        - Roihu
    - Roihu
---

# COMSOL Multiphysics

The COMSOL Multiphysics simulation environment facilitates
all steps in the modeling process; defining your geometry, specifying
your physics, meshing, solving and then post-processing your results.

Setting up the model is quick, thanks to a number of predefined modeling
interfaces for applications ranging from fluid flow and heat transfer to
structural mechanics and electromagnetic analyses. Material properties,
source terms and boundary conditions can all be arbitrary functions of
the dependent variables.

[TOC]

## Available
COMSOL is available on CSC's [Roihu](../computing/available-systems.md) supercomputer on both the CPU and GPU (aarch64) partitions.

## License
The terms of use of this software allow it to be used only by affiliates (staff
and students) of Finnish higher education institutions.

## Usage
The following modules are currently available:

-   Acoustics
-   AC/DC
-   CAD Import
-   CFD
-   Heat Transfer
-   Particle Tracing
-   Structural Mechanics

To find out which versions of COMSOL are installed on Roihu, give a command
```bash
module available
```
and check lines `comsol/<version number>`. For example, to load comsol version 6.4, give a command
```bash
module load comsol/64
```

There are example **batch job files** available on Roihu server in directories
```bash
/appl/soft/manual/eng/x86_64/comsol/example_batch_job_scripts
```
and
```bash
/appl/soft/manual/eng/aarch64/comsol/example_batch_job_scripts
```
Copy the file and modify it for your own use.

The preferred method to use COMSOL interactively is via [the Roihu web interface](../computing/webinterface/desktop.md). In the web interface,
select `Desktop` from the `Apps` view and specify the required resources (cores,
execution time and memory). Remember to add your billing project, too.

Wait for a while as your interactive job sits in the queue and after that you can start
COMSOL with double-clicking its icon (tick the box if you want to receive an email when your session starts).

!!! Note
    You can now also enable [interactive visualization with GPU
    acceleration](../computing/webinterface/accelerated-visualization.md) for better
    performance. In this case, select `Accelerated visualization` instead of `Desktop`
    in the Roihu web interface.

    See the section below for details.

Sometimes, you may encounter errors relating to OpenGL rendering during
the launch. The solution is to force COMSOL to start with software
rendering from Desktop app `Terminal` using

```bash
module load comsol
comsol -3drend sw
```

### Accelerated visualization in Roihu

On Roihu's web interface, you can optionally choose to use the accelerated visualization desktop session to run COMSOL for more
intensive visualization tasks.

1. Connect to the [Roihu web interface](../computing/webinterface/connecting.md).
2. Select the [Accelerated Visualization](../computing/webinterface/accelerated-visualization.md)
   app of the web interface and specify the required resources.
3. Click the *Launch* button. Your job is placed in the queue, and once it has
   been allocated resources, click *Launch Accelerated Visualization*.
4. Launch COMSOL from *Applications* > *Computational Engineering* > *COMSOL (Accelerated)* (or search
   for it using the *Application Finder*). Launching the software may take a
   few seconds, so be patient.

![Launching COMSOL in Roihu web interface accelerated desktop](../img/comsol_interactive_roihu.png 'Launching COMSOL in Roihu web interface accelerated desktop')

## Support
In case of issues, please [contact CSC Service Desk](../support/contact.md).

## More information
- [COMSOL Multiphysics home page](https://www.comsol.com)
