# This month in AvaFrame - January 2021 edition

## January 30, 2021

Welcome to the first instalment of our monthly update of 2021. This month we started getting into the nitty-gritty of our dense flow module’s numerical implementation:

- To facilitate and improve our development we added new test cases. This time they are more geared towards testing specific numerical issues and more targeted issues, concentrating for now on the dense flow module com1DFAPy.

  - flat plane: a pile of sand (i.e. particles with coulomb friction) on a flat plane. The pile should or should not move depending on the steepness of the sides of the pile

  - inclined slope: similar to the previous, a pile of sand (coulomb friction again) flowing down an inclined plane. This test enables comparison to a solution described in Savage-Hutter 1993 in which the depth and velocity profiles can be determined in an analytical form.

  - (rotated) pyramid: generation routines to produce a, potentially rotated and/or shifted, pyramid with a release area at the top of the pyramid. This allows for checking of rotational symmetry, among others.

- We are currently looking at and analysing how to place the initial particles and what effect this has further along the simulation.

- Getting into the numerical development also means the compute times start to play a role. We moved some parts of the code over to Cython to improve the computation efficiency of the python dense flow kernel. We are starting to profile our python code (pudb and cProfile for those interested).

- For general analysing with ana3AIMEC: after some deliberation we decided to move the (arbitrary) starting point of our runout calculation to the top of the main avalanche profile (instead of some point further down the profile). See our definitions for this in the glossary. If this makes you internally scream in agony because we got it all wrong, feel free to contact us!

- We have a ton of minor changes which however improve usability quite a lot. That means mundane (some might say boring) things like enabling underscores in input names, consistent naming of result variables, extended export capabilities (more time steps), and many more.

- Bringing AvaFrame to the Windows world is also currently high on our priority list. We explored options on the best ways to install and maintain an AvaFrame installation on as many Windows versions as possible. Expect some exciting news on this one in the next few weeks.

As you can see, we are off to a good start this year! As always please contact us with any questions or issues you have!

Felix

Want to contact us? Visit our matrix room at: #public:matrix.avaframe.org