Hi Chi Hin

Thanks. You are right about the velocity gradient alone. Sorry, I didn't ask the right question. 
What can be done when we have a product of velocity gradients? 
More precisely, I need to calculate the TKE viscous dissipation term:
nu*<s_ij s_ij>,
where s_ij refers to the fluctuation strain rate tensor. I need this quantity to subsecuently calculate the Kolmogorov length scale.
I see it calculated in a paper that has utilized Nektar++, but I have not a clear idea how it was done.

Kind regards
syavash

On Sun, Jun 18, 2023, 14:03 Chan, Chi Hin <chi.chan19@imperial.ac.uk> wrote:
Hi Syavash,

You could use FieldConvert -m gradient on the time-averaged fields.

Regards,
Chi Hin

Get Outlook for iOS
From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Ehsan Asgari <eh.asgari@gmail.com>
Sent: Saturday, June 17, 2023 8:20:29 PM
To: nektar-users <nektar-users@imperial.ac.uk>
Subject: [Nektar-users] Time-average of a gradient
 

This email from 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 to disable email stamping for this address.

 

Dear All,

How may I calculate the time-average of a gradient, for example velocity gradient?

Kind regards
syavash