Hi YiLin, I don't have experience with acoustic solver, however I use restart often in my simulations with inc NS solver. I is pretty straight forward to do so, imaging you run your simulations for some time and you have checkpoint file (or fld file) of the results you want to use it for a new simulaiton as a restart. lets name this output result myrestult_100.chk First I rename it to an appropriate name, though you can leave the name or extension as is. I usually rename it to sth like "myresults.rst" now in the session file, inside "CONDITIONS" tag, define a function as follow </CONDITIONS> <!-- other settings and stuff --> <FUNCTION NAME="InitialConditions"> <F VAR="u,v,p" FILE="myresults.rst" /> <E VAR="w" VALUE="0.005*awgn(1.)" /> </FUNCTION> </CONDITIONS> Note that the tag "F" represents file where I supplied the name of restart file. Also, note that I put the variables name "u,v,p" that should be read from this file. In this example I assumed my restart file is from a 2D solution and I need to use it for a 3D one. so I have u, v and p from the restart. for the w component of the velocity that I do not have I defined a function to be evaluated. it is a random distrubance. I could have simply set w to zero <E VAR="w" VALUE="0" /> or any other function or value that I shall desire. if I had results from a 3D simulation to be used for a new 3D one (or 2D for 2D), you only need to provide the file name and delete the second line corresponds to w. I believe you get the idea how to proceed in different situations. Hope it helps. Cheers, Mohsen ________________________________ From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Paul Liu <liuyilin.liu@gmail.com> Sent: Thursday, February 10, 2022 4:46 PM To: nektar-users <nektar-users@imperial.ac.uk> Subject: [Nektar-users] General Information- Restarting simulations This email from liuyilin.liu@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. Hi Everyone, I was wondering if there is a section outlining how to restart simulations using the pre-built solver in NEKTAR++, specifically the AcousticSolver? I have not found a section in the user guide outlining how to restart simulations. Thank you. YiLin Liu 403-397-3457 liuyilin.liu@gmail.com<mailto:liuyilin.liu@gmail.com> MASc Student at CML<https://cml.mech.ubc.ca/> UBC