# How can I use EDAC in PyFR when simulating the incompressible problem? **URL:** \ **Category:** General\ **Created:** [22 July 2022 06:20 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653 "2022-07-22T06:20:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![luli](https://avatars.discourse-cdn.com/v4/letter/l/5f9b8f/32.png) [@luli](https://pyfr.discourse.group/u/luli)\ **Post date:** [22 July 2022 06:20 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/1 "2022-07-22T06:20:04Z")
I have read paper [[2111.07915] Artificial Compressibility Approaches in Flux Reconstruction for Incompressible Viscous Flow Simulations (arxiv.org)](https://arxiv.org/abs/2111.07915), and found a method called EDAC are used in PyFR framework, what should I do to use this method ? Should I change config.ini file ? Are there any reference config.ini files? ---
**Author:** ![WillT](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@WillT](https://pyfr.discourse.group/u/WillT)\ **Post date:** [22 July 2022 13:00 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/2 "2022-07-22T13:00:45Z")
This isn’t a fully supported feature of PyFR and we don’t have any plans for EDAC to become our defacto method for incompressible flows. However, my implementation can be found here: [GitHub - WillTrojak/PyFR at feature/entropic\_damping](https://github.com/WillTrojak/PyFR/tree/feature/entropic_damping) There is no documentation for this branch, so you’ll have to look at the source code to see how to configure it. Generally most of the features of the ACM approach are transposed and supported with EDAC but with the names changed to `ed-...` rather than `ac-...`, and of course you can run explicitly which I would recommend doing with global adaptive time stepping. ---
**Author:** ![luli](https://avatars.discourse-cdn.com/v4/letter/l/5f9b8f/32.png) [@luli](https://pyfr.discourse.group/u/luli)\ **Post date:** [25 July 2022 02:49 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/3 "2022-07-25T02:49:03Z")
Thank you very much !!! ---
**Author:** ![randommc](https://avatars.discourse-cdn.com/v4/letter/r/e56c9b/32.png) [@randommc](https://pyfr.discourse.group/u/randommc)\ **Post date:** [26 July 2022 05:35 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/4 "2022-07-26T05:35:30Z")
Why don’t you choose EDAC method to become your defacto method for incompressible flows? Does the method have some disadvantages? ---
**Author:** ![WillT](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@WillT](https://pyfr.discourse.group/u/WillT)\ **Post date:** [26 July 2022 07:37 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/5 "2022-07-26T07:37:03Z")
I cover the reasons in the paper, the main issue is robustness on features sensitive to errors in the pressure feild. In EDAC, the pressure field has a secondary role of counteracting velocity divergence and the scaling of this is dependent on the zeta quantity. Potentially some zeta adaptive method would be a good idea, but I think this requires a seperate paper. ---
**Author:** ![Jiajun](https://avatars.discourse-cdn.com/v4/letter/j/76d3ee/32.png) [@Jiajun](https://pyfr.discourse.group/u/Jiajun)\ **Post date:** [5 March 2025 08:30 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/6 "2025-03-05T08:30:30Z")
Im really curious about the zeta adaptive method mentioned here. Could you please share some details about that? ---
**Author:** ![WillT](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@WillT](https://pyfr.discourse.group/u/WillT)\ **Post date:** [26 March 2025 15:54 UTC](https://pyfr.discourse.group/t/how-can-i-use-edac-in-pyfr-when-simulating-the-incompressible-problem/653/7 "2025-03-26T15:54:41Z")
We never got around to implementing the adaptive zeta work, but you are more than welcome to take a look at it.