Thanks Chi Hin Are you implying that WSS module would automatically utilize the time-averaged velocity in the fld file? Inside the fld file I have Reynolds stress as well. So I was unsure how WSS would recognize the components of the time-averaged velocity field. Kind regards syavash On Tue, Jun 6, 2023, 15:12 Chan, Chi Hin <chi.chan19@imperial.ac.uk> wrote:

Hi Syavash

You could use FieldConvert’s WSS module. For instance, if the wall boundary ID is 0,

FieldConvert -m wss:bnd=0 <mesh.xml> <session.xml> <time-averaged.fld> <time-averaged-wss.fld>

The output fld will either be a 1D/2D field of wss values on the boundary ID for a 2D/3D flow field.

If you wish to compute mean of the wss, you can use FieldConvert -m mean with the appropriate 1D/2D mesh file of the boundary obtained using Nekmesh -m extract. Hope this helps

Cheers Chi Hin

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Dear All,

I have a time-averaged field, say "time-average.fld". How should I proceed to calculate time-averaged wall shear stress? I was wondering if I need to use "wss" first.

Kind regards syavash