[RobBanks]

Hello anyone and everyone.

I have this issue: I'm running some simulations and they go and end entirely normal, but when I check the results I find that I need to extend this simulations in order to obtain steady values through time for the required variables.

When I re-start the simulation from the last .res file and also from the last .trn file, it only performs one, two or maybe three outer loop iterations and it ends, perfectly by the way, but it is not enough because it doesn't finishes the entire simulation time. It only does a few timesteps and finishes, normally.

How could I set the parameters to force the program into doing the entire simulation time and performing more timesteps?? Because it doesn't errs at any point, it just finishes before time in a "perfectly normal" fashion.

The simulations are in transient regime.

Thanks in advance for any of your helpful replies.

[-Maxim-]

why does the simulation stop? What does the out file day? Did it reach your convergence criteria? If yes, you need to change that.

[Red Ember]

during solution:
push the button dynamically edit the settings of the run in progress - flow analysis - solver control? then:
- convergence control - increase max number of iteration (if all iterations were performed)
- convergence criteria - decrease residual target value (if RMS/MAX residuals met this criterium too early)

[urosgrivc]

I dont think this has anithing to do with convergence, because it is transient,unless it exits with errors:

-Just increese the simulation time, or did I misunderstood you

it finishes before what time? the one that you set as simulation time?

[RobBanks]

Originally Posted by -Maxim-

why does the simulation stop? What does the out file day? Did it reach your convergence criteria? If yes, you need to change that.

I don't know why it stops. The out file says that it ended "perfectly normal". It does reach the convergence criteria but it does all that very fast. It doesn't even generates one .trn file and I need those for the mesh independece study.

[RobBanks]

Originally Posted by Red Ember

during solution:
push the button dynamically edit the settings of the run in progress - flow analysis - solver control? then:
- convergence control - increase max number of iteration (if all iterations were performed)
- convergence criteria - decrease residual target value (if RMS/MAX residuals met this criterium too early)

I've done this before, I've increased the number of iterations but it still finishes quite fast.
I think I couldn't set the RMS residuals lower, because they naturally go way below 1.0E-5 and when the sim starts, the previous one had reached that criteria already, it just registers a slight perturbation and the values go up and they inmmediately go down. Sometimes they don't even go up, it does only one or two iterations and ends, normally,

[RobBanks]

Originally Posted by urosgrivc

I dont think this has anithing to do with convergence, because it is transient,unless it exits with errors:

-Just increese the simulation time, or did I misunderstood you

it finishes before what time? the one that you set as simulation time?

I think in this reply lies the issue. On the Pre Steup, when I set the simulation time, the timesteps and the time when it is going to start, I have lately changed the configuration of the parameter of the time when it will begin and that has helped a bit, now it does more iterations but, when I set that parameter to start on the very moment the previous one ended, when simulating, it doesn't continues the simulation where they had finished but it does a perturbation on the RMS graphics and starts behaving in a different way than the previous one and I only changed the Time when it will start, I don't change any of the parameters from the previous one to the new one... Shouldn't it keep doing what it was doing before? Is there any way to make one simulation that ended normally continue doing some more iterations without that perturbation? I think that fixing those parameters, the "Time when it will start" and the "Simulation time" fixes the issue I explained in my first message but now there is this other one. This new simulation also finish in a "perfectly normal" fashion, so there are no errors.