# How do I know if my simulation runs well?

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 January 6, 2019, 16:53 How do I know if my simulation runs well? #1 New Member   David Join Date: Oct 2018 Posts: 27 Rep Power: 7 Hello all, I am new to CFD-Simulations and after I set up my first case in interFoam I am wondering if my simulation runs to slow. Are there any characteristics I can check to see if the simulations runs with a appropriate speed. I've already found out that when the Courant Number increases or the deltaT decreases too much that these are good characteristics to see that there is something wrong with some conditions. For example I'll post some lines of the shell below. For thise Case I first did a simulation with a very coarse mesh which did run quite well without any errors. After if refined the mesh the simulations takes a lot of time and like I said I am not sure if it's just because of the finer mesh or if some boundarie conditions are wrong. Thanks in advance David case.zip HTML Code: ```Courant Number mean: 0.051790448 max: 1.1206113 Interface Courant Number mean: 0.0049403903 max: 0.93649679 deltaT = 0.015620568 Time = 12.8594 PIMPLE: iteration 1 smoothSolver: Solving for alpha.water, Initial residual = 0.003574985, Final residual = 1.2198356e-009, No Iterations 4 Phase-1 volume fraction = 0.0069168399 Min(alpha.water) = -4.9982028e-006 Max(alpha.water) = 1.0000002 MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.0069168406 Min(alpha.water) = -0.0027150452 Max(alpha.water) = 1.0002525 smoothSolver: Solving for Ux, Initial residual = 0.0024374319, Final residual = 0.00016418998, No Iterations 1 smoothSolver: Solving for Uy, Initial residual = 0.0029438757, Final residual = 0.00022770844, No Iterations 1 smoothSolver: Solving for Uz, Initial residual = 0.012344524, Final residual = 0.00096820841, No Iterations 1 GAMG: Solving for p_rgh, Initial residual = 0.0223709, Final residual = 0.00015670417, No Iterations 2 GAMG: Solving for p_rgh, Initial residual = 0.00066884765, Final residual = 4.5459619e-006, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 0.00010618805, Final residual = 5.5520633e-007, No Iterations 3 time step continuity errors : sum local = 5.093267e-008, global = -1.7406469e-008, cumulative = -4.3114422e-006 GAMG: Solving for p_rgh, Initial residual = 0.0013193478, Final residual = 4.7956439e-006, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 0.00011301249, Final residual = 4.4441165e-007, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 2.0171242e-005, Final residual = 9.25677e-008, No Iterations 3 time step continuity errors : sum local = 8.4866827e-009, global = 2.5894171e-009, cumulative = -4.3088528e-006 PIMPLE: iteration 2 smoothSolver: Solving for alpha.water, Initial residual = 0.0032416862, Final residual = 9.1914122e-010, No Iterations 4 Phase-1 volume fraction = 0.00691684 Min(alpha.water) = -4.8085559e-006 Max(alpha.water) = 1.0000002 MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.0069168406 Min(alpha.water) = -0.0024832499 Max(alpha.water) = 1.0002574 smoothSolver: Solving for Ux, Initial residual = 0.0015384606, Final residual = 9.1613033e-005, No Iterations 1 smoothSolver: Solving for Uy, Initial residual = 0.001684108, Final residual = 0.00011784075, No Iterations 1 smoothSolver: Solving for Uz, Initial residual = 0.0054832419, Final residual = 0.00029107622, No Iterations 1 GAMG: Solving for p_rgh, Initial residual = 0.0023800499, Final residual = 1.9460927e-005, No Iterations 2 GAMG: Solving for p_rgh, Initial residual = 0.0001535107, Final residual = 9.3338449e-007, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 2.6699164e-005, Final residual = 1.3347999e-007, No Iterations 3 time step continuity errors : sum local = 1.2211031e-008, global = 2.0274662e-009, cumulative = -4.3068254e-006 GAMG: Solving for p_rgh, Initial residual = 0.00012309092, Final residual = 4.6944927e-007, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 1.3389387e-005, Final residual = 4.8603763e-008, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 2.4859023e-006, Final residual = 3.1315433e-008, No Iterations 2 time step continuity errors : sum local = 2.8654481e-009, global = -4.385919e-010, cumulative = -4.307264e-006 PIMPLE: iteration 3 smoothSolver: Solving for alpha.water, Initial residual = 0.003252499, Final residual = 9.2321705e-010, No Iterations 4 Phase-1 volume fraction = 0.00691684 Min(alpha.water) = -4.5039744e-006 Max(alpha.water) = 1.0000002 MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.0069168406 Min(alpha.water) = -0.002529705 Max(alpha.water) = 1.0002668 smoothSolver: Solving for Ux, Initial residual = 0.0011599909, Final residual = 9.006172e-009, No Iterations 7 smoothSolver: Solving for Uy, Initial residual = 0.001369171, Final residual = 5.2600945e-009, No Iterations 8 smoothSolver: Solving for Uz, Initial residual = 0.0034087053, Final residual = 3.4716123e-009, No Iterations 9 GAMG: Solving for p_rgh, Initial residual = 0.0081285992, Final residual = 7.3141984e-005, No Iterations 2 GAMG: Solving for p_rgh, Initial residual = 0.00038799975, Final residual = 2.7431327e-006, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 6.767316e-005, Final residual = 3.0605883e-007, No Iterations 3 time step continuity errors : sum local = 4.6038218e-008, global = 4.6559063e-009, cumulative = -4.302608e-006 GAMG: Solving for p_rgh, Initial residual = 0.0003258291, Final residual = 8.9802616e-007, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 3.1587352e-005, Final residual = 1.0951785e-007, No Iterations 3 GAMG: Solving for p_rgh, Initial residual = 5.9103347e-006, Final residual = 7.2510559e-008, No Iterations 2 time step continuity errors : sum local = 1.0917308e-008, global = 4.5101177e-010, cumulative = -4.302157e-006 ExecutionTime = 4424.827 s ClockTime = 4425 s Courant Number mean: 0.05183831 max: 1.122726 Interface Courant Number mean: 0.004955322 max: 0.94199071 deltaT = 0.015620568 Time = 12.875```

 Tags boundaries, courant number, deltat, interfoam, simulation