Hello Selman, how are you? i. I think you could do that with your boundary condition on the wall, simply implementing the value of the velocity on the specific component. Also, you can use boolean operators to limit the region and also time to specify the period. There is (or are) an explanation of that in the user guide. Also, If it's not on the boundary, you could use a body force, also using boolean operators and a time flag for the specific period. ii. The Reynolds stress filter will compute the time average of your solution as well as the time-averaged Reynolds stresses. If you compare the results obtained from it with the ones from a history file, they will eventually be the same, but as the average process is different for the filter, they differ for short average periods. At least that was my experience with it. I hope it helps and I wish you luck, Daniel. Em sex., 23 de ago. de 2024 às 07:15, Selman BAYSAL < selmanbaysal@comu.edu.tr> escreveu:

This email from selmanbaysal@comu.edu.tr 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 two different questions that I would greatly appreciate your insights on:

1. I'm currently investigating the laminar-to-turbulent transition in oscillatory wave boundary layers. For some time, I have been using a roughness element to generate initial perturbations. However, I would like to find out how to define a fluid jet (i.e., vertical velocity v = A where A is a constant) that puffs puffing for a while (e.g., from t0 to t1) from a specific point at the bed (e.g., x=y=z=0 at the boundary "2"). Is it possible to implement this in Quasi-3D approach? 2. I have implemented "Reynolds stresses" filter into my XML code and obtained output files without any problem. However, when I compared these output files with the original checkpoint file (*.chk), I observed noticeable discrepancies in the velocity and pressure variables. The raises concern about the accuracy of other variables such as uu, uv, vw, etc. Could you please clarify what exactly this filter outputs?

Thank you very much for your time and intention. Any advice or recommendations you can provide would be greatly appreciated!

Best regards,

Selman Baysal R. A. in Hydraulics Dept. of Civil Eng'g Çanakkale Onsekiz Mart University -- ITU Civil Eng., BSc. ITU Coastal Sci. & Eng., MSc. _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users