maxCo in constant/sprayCloudProperties in OpenFOAM and in system/controlDict

Altosmos · May 10, 2020, 11:44

Hi all,
i am new to the SprayFoam solver in OpenFoam and noticed that my simulation crashes due to the maxCo numbers. But to be able to understand the problem there, i need to understand why we are giving in 2 different Co-Numbers for a Simulation. Is one for the Lagrangian phase and the other for the Euler Phase? If yes, how does that make a difference, since the time step and the mesh stays the same?

Thanks for all the answers
Wish you all have a good and healthy day

geth03 · May 29, 2020, 04:03

i think you mean the
meanCoNum and maxCoNum, right?

the one with the higher value is the maximal Courant number available in your domain that sets your timestep, if you enabled timestep adjustment with regards to the Courant number.

the other one is just the mean Courant number, the average to say, which doesn't give sufficient information.

so the time step limiting factor is the maximal Courant number, which is the more important number of those two.

May 10, 2020, 11:44	maxCo in constant/sprayCloudProperties in OpenFOAM and in system/controlDict	#1
Altosmos New Member Altay Join Date: Nov 2019 Posts: 6 Rep Power: 6	Hi all, i am new to the SprayFoam solver in OpenFoam and noticed that my simulation crashes due to the maxCo numbers. But to be able to understand the problem there, i need to understand why we are giving in 2 different Co-Numbers for a Simulation. Is one for the Lagrangian phase and the other for the Euler Phase? If yes, how does that make a difference, since the time step and the mesh stays the same? Thanks for all the answers Wish you all have a good and healthy day

May 29, 2020, 04:03		#2
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	i think you mean the meanCoNum and maxCoNum, right? the one with the higher value is the maximal Courant number available in your domain that sets your timestep, if you enabled timestep adjustment with regards to the Courant number. the other one is just the mean Courant number, the average to say, which doesn't give sufficient information. so the time step limiting factor is the maximal Courant number, which is the more important number of those two. Altosmos likes this.