Great, glad we found the problem. Just in case, we have several tutorials here (https://www.nektar.info/notebooks/) that might be helpful and save you times. Unfortunately, for some technical issues we cannot try them on web in Jupyter lab env but the explanations are detailed. I would look at this one in particular (https://www.nektar.info/notebooks//tutorials/basics-incns-solver/<https://www.nektar.info/notebooks/tutorials/basics-incns-solver/>) There are tutorials in other formats too (https://www.nektar.info/getting-started/tutorials/) which are basically different from the ones in notebooks. Finally, in nektar++/solvers/IncNavierStokesSolver/Tests you can find many simple tests where sometimes could be helpful. Such tests are available for other solvers too Eraadat, Mohsen From: Ehsan Asgari <eh.asgari@gmail.com> Date: Tuesday, 4 April 2023 at 21:42 To: Mohsen Lahooti <Mohsen.Lahooti@newcastle.ac.uk> Cc: nektar-users@imperial.ac.uk <nektar-users@imperial.ac.uk> Subject: Re: [Nektar-users] Reynolds stress field not written Hi Mohsen, mokhlesam! Thank you for your kind help. That is what I missed! Kind regards syavash On Tue, Apr 4, 2023 at 11:34 PM Mohsen Lahooti <Mohsen.Lahooti@newcastle.ac.uk<mailto:Mohsen.Lahooti@newcastle.ac.uk>> wrote: Hi Syavash, I assume you enclosed the filter in a filters tag as below, right? If you have other filters, all goes inside <FILTERS> …. </FILTERS> tags too. Eg. If you have FilterAeroforces too, all will looks like: <FILTERS> <FILTER TYPE="ReynoldsStresses"> <PARAM NAME="OutputFile">step95_4_averageField.fld</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="SampleFrequency"> 1 </PARAM> </FILTER> <FILTER TYPE=”AeroForces”> <PARAM NAME=”OutputFile”>forces</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="SampleFrequency"> 1 </PARAM> </FILTER> </FILTERS> Hope this helps, Cheers, Mohsen From: nektar-users-bounces@imperial.ac.uk<mailto:nektar-users-bounces@imperial.ac.uk> <nektar-users-bounces@imperial.ac.uk<mailto:nektar-users-bounces@imperial.ac.uk>> on behalf of Ehsan Asgari <eh.asgari@gmail.com<mailto:eh.asgari@gmail.com>> Date: Tuesday, 4 April 2023 at 19:53 To: nektar-users@imperial.ac.uk<mailto:nektar-users@imperial.ac.uk> <nektar-users@imperial.ac.uk<mailto:nektar-users@imperial.ac.uk>> Subject: [Nektar-users] Reynolds stress field not written ⚠ External sender. Take care when opening links or attachments. Do not provide your login details. This email from eh.asgari@gmail.com<mailto:eh.asgari@gmail.com> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear All, I have added the ReynoldsStresses filter to the main Nektar block in my session file: <FILTER TYPE="ReynoldsStresses"> <PARAM NAME="OutputFile">step95_4_averageField.fld</PARAM> <PARAM NAME="OutputFrequency">10</PARAM> <PARAM NAME="SampleFrequency"> 1 </PARAM> </FILTER> I am doing parallel simulations using 128 cores. However, I get no Reynolds stress fields in my directory. I don't get any errors or warnings either. Am I missing something? Kind regards syavash