Hi Marcus, Transition can often take considerable time. For example, if instead you were looking at turbulent pipe flow, it is not unusual for transition to occur only after 100 time units. You could probably use a slightly larger time-step initially and check point every 5-10 time units. When transition occurs the simulation will probably blow up, but then you can restart from your previous check-point file with a lower time-step. This might save you some time. Have you monitored and plotted the modal energies using the ModalEnergy filter? If you can post a plot of your modal energies we can see if it looks like what we expect. Cheers, Chris On 08/06/16 22:41, Lander, Marcus David wrote:

So, I have been running through all the examples given thus far, and I’m curious about the Turbulent Channel Flow example. I have been running the simulation for a decent amount of time, but I still do not seem to be gaining a solution that resembles what is shown in the user guide. I have also included the recommended modifications made in this post: https://mailman.ic.ac.uk/mailman/htdig/nektar-users/2016-May/000371.html

My questions regarding the turbulent channel case are:

1)Approximately how long does the simulation need to run in terms of “in-simulation-time” before I can expect to see something similar to what is shown in the user-guide? Currently, mine is at 26.8299 seconds, with a time-step of 0.0001 (as per the original example).

2)When the case in the user-guide was generated, was it done in serial??? I have been running this in parallel to try and speed it along because our job queue only allows us one hour of execution at a time.

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-- Chris Cantwell Imperial College London South Kensington Campus London SW7 2AZ Email: c.cantwell@imperial.ac.uk www.imperial.ac.uk/people/c.cantwell