Message by Hodong Lee:
In addition to the previous question of CEX,
I also have a problem with too slow simulation speed.
I am running SPIS 6.0.0 with 24 GB RAM, but what bothers me is too small simulation dt while running the simulation.
The number of tetrahedrons in the mesh I made is about 65,000, with a not bad mesh quality.
I want to simulate a relatively short duration of 1 ms for a hall thruster, but simulation dt is in the range of 10^(-10) ~ 10^(-9).
I tried to decrease the number of avPartNbPerCell to 2.0, and change electronDistrib and ionDistrib as UnlimitedGlobalMaxwellBoltzmannVolDistrib, with other particles related to thruster (Xe+, CEX Xe+, etc) as PIC.
Are there other parameters I should change in order to get a reasonable simulation speed?
Or, is it originally (inevitably) so slow?
I am desperately waiting for a reply.
The following information is the parameters I used in my simulation:
About maximum intergration time step
electron dt: 1.0E-7
electron duration: 2.5E-7
ion dt : 1.0E-6
ion duration : 5.0E-6
plasma dt: 5.0E-7
plasma duration: 1.0E-6
simulation dt: 1.0E-5
simulation dt init: 1.0E-6
duration: 1.0E-3
VolInteract Parameters
parameter1VolInteract#:0.05
parameter2VolInteract#:0.2
parameter3VolInteract#:1.0
parameter4VolInteract#:2.9E-4
volInteract#: 0.5
crossSectionVolInteract1 (for Xe+): 8.0E-19
crossSectionVolInteract2 (for Xe++): 2.0E-19
About Poisson Equation:
iterGradient: 1500
iterGradientNI: 2000
iterLinearSys: 10000
iterNewton: 200
regular Poisson computation
tolGradient:1.0E-5
tolGradientNI: 1.0E-5
TolLinearSys: 1.0E-12
tolNewton: 0.005
variableTe:1
variableTeConstant: 6.07E-4
variableTegamma:1.23
Thank you.
Hodong Lee.