# Time step continuity errors

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 July 26, 2011, 11:32 Time step continuity errors #1 New Member   Unnikrishnan Join Date: Jun 2011 Posts: 10 Rep Power: 8 Sponsored Links Dear Foamer, I have the following doubt. In Fueltank Simulation with Gasoline and Air. using InterFoam Solver.. I have the problem with the Simulation taking a long time to run. Case 1: MULES: Solving for alpha1 Liquid phase volume fraction = 0.26 Min(alpha1) = -8.2e-45 Max(alpha1) = 1 MULES: Solving for alpha1 Liquid phase volume fraction = 0.26 Min(alpha1) = -6.1e-44 Max(alpha1) = 1 FDICPCG: Solving for p, Initial residual = 9.5e-05, Final residual = 9.8e-08, No Iterations 135 FDICPCG: Solving for p, Initial residual = 4.5e-05, Final residual = 9.5e-08, No Iterations 131 time step continuity errors : sum local = 3.4e-09, global = 9.7e-12, cumulative = -0.55 ExecutionTime = 2.1e+03 s ClockTime = 2128 s Courant Number mean: 0.013 max: 0.5 deltaT = 8.4e-05 Time = 0.0037 Case 2: MULES: Solving for alpha1 Liquid phase volume fraction = 0.284091 Min(alpha1) = 0 Max(alpha1) = 1 MULES: Solving for alpha1 Liquid phase volume fraction = 0.284122 Min(alpha1) = 0 Max(alpha1) = 1 DICPCG: Solving for p, Initial residual = 0.00298799, Final residual = 0.000131926, No Iterations 9 DICPCG: Solving for p, Initial residual = 0.000792862, Final residual = 3.83134e-05, No Iterations 24 DICPCG: Solving for p, Initial residual = 0.000115893, Final residual = 7.5165e-08, No Iterations 190 time step continuity errors : sum local = 1.06601e-08, global = 3.61895e-10, cumulative = -1.09828e-08 ExecutionTime = 51.02 s ClockTime = 51 s With Case 1 0 -> 0.0021 ( 1392 s ) 0 -> 10 ( 1841.2 hrs ) I want to reduce the total Time for Simulation. I had tried changing the ControlDict But there is no change deltaT 0.1; -> 0.01 ->0.001 writeControl adjustableRunTime; writeInterval 0.005; -> 0.0005 ->0.00005 (for 0.00005 i am able to find some Writefiles and Some results in openfoam ) Trials done : I had tried Changing the Pressure values, I had tried Changing the Velocity Values, Maintaining different Values at both Ends. But there is no change in simulation timings. Changing Fvsolution Pcorr DIC -> FDIC reltol 0 -> 1e-05 P DIC -> FDIC reltol 0 -> 1e-03 pfinal DIC -> FDIC reltol 0 -> 1e-03 U reltol 0 -> 1e-03 Piso ncorrector 3 -> 2 But still there is not change in the following problem.. I would first like the check if the simulation is running.. I could latter check about the results.. Regards Unnikrishnan

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