Hi Chengeng,

In CFD, local time stepping means that each element is updated from the local value of the time step computed from the specified CFL number. Local time stepping is used to accelerate convergence to the steady state solution as each element is updated by different value of time step, the solution obtained is not time-accurate (unless combined with an approach such as dual-time stepping).

Best,
Jacques
From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of Chengeng Qian <qiancg0313@gmail.com>
Sent: Friday, March 10, 2023 8:15 AM
To: nektar-users@imperial.ac.uk <nektar-users@imperial.ac.uk>
Subject: [Nektar-users] Parameters for local time stepping
 
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Hi everyone,
What is following parameter used for?

<I PROPERTY="LocalTimeStep"         VALUE="True" />

I though that it must be ture if we calculated time step using CFL. But I found that I could run case with LocalTimeStep = False. In addition, the result obtained by LocalTimeStep = Ture is more closed to the steady solution. Any comments are appreciated.

Cheers,
Chengeng.