Viscous Time Step Calculation

c.atkins · January 15, 2018, 07:52

Hi,

I have a query regarding the time step calculation in viscous simulations.

The CNSSolver::SetTime_Step routine adds together the lambda for viscosity and the lambda for thermal conductivity. I was under the impression that one should take the maximum of those to determine the timestep - but I could well be wrong?

I have tried to find a definitive answer and couldn't, so would someone be able to give me a reference/explanation as to why the timestep is calculated in this way?

Thanks,

Chay

fpalacios · February 24, 2018, 12:57

Like a lot of stuff in these software the reason is test and error, historical reasons and a conservative solution. If I were you I would try you proposal and if it better just create a pull request. By the way if you are a developers check out the SU2 IDS www.su2devsociety.org

Best,
Francisco

January 15, 2018, 07:52	Viscous Time Step Calculation	#1
c.atkins New Member C. Atkins Join Date: Oct 2016 Posts: 6 Rep Power: 9	Hi, I have a query regarding the time step calculation in viscous simulations. The CNSSolver::SetTime_Step routine adds together the lambda for viscosity and the lambda for thermal conductivity. I was under the impression that one should take the maximum of those to determine the timestep - but I could well be wrong? I have tried to find a definitive answer and couldn't, so would someone be able to give me a reference/explanation as to why the timestep is calculated in this way? Thanks, Chay

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February 24, 2018, 12:57		#2
fpalacios Super Moderator Francisco Palacios Join Date: Jan 2013 Location: Long Beach, CA Posts: 404 Rep Power: 15	Like a lot of stuff in these software the reason is test and error, historical reasons and a conservative solution. If I were you I would try you proposal and if it better just create a pull request. By the way if you are a developers check out the SU2 IDS www.su2devsociety.org Best, Francisco