Hi Cheng, As you mention we had a previous discussion on this topic. I think the issue is that we are not dealiaising the statistics when calculating the Reynolds stresses. So ideally we need to write and process them at a higher number of quadrature points and that will hopefully make it more accurate and smoother. I think others have had to write many output files and then post-process these files which unfortunately takes a lot of disk space. Best, Spencer. From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Xiao, Chengnian <CHX33@pitt.edu> Date: Wednesday, 25 September 2024 at 02:03 To: nektar-users <nektar-users@imperial.ac.uk> Subject: [Nektar-users] Wiggles in turbulent dissipation rate profile This email from CHX33@pitt.edu 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, Hope everyone is doing well! We keep seeing wiggles in our time- and plane-averaged profile for the turbulent dissipation rate \epsilon obtained from Nektar++ DNS results, as shown in the attached plot. They seem to appear whenever calculating profiles of second or higher order flow statistics involving velocity gradients, whereas the time-averaged flow profiles themselves look alright. From earlier posts, it seems that similar issues have also been reported by other users. Is there a way to alleviate the issue either through adapting the simulation or the postprocessing procedure, i.e. smoothing? Best regards, Cheng