# Orifice Plate with a fully developed flow - Problems with convergence

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 June 3, 2011, 18:50 Orifice Plate with a fully developed flow - Problems with convergence #1 New Member   Jonathas Assunção de Castro Join Date: Mar 2009 Posts: 11 Rep Power: 9 Hy .... i'm trying to simulate the pressure drop caused by the obstruction in a orifice plate. So i generated a duct upstream the obstruction with the purpose of obtaining a fully developed flow before the hole. However simpleFoam doesn't converge. Please, help me. My term is ending and I still did not achieve satisfactory results. My turbulence model is kepsilon. CheckMesh is OK. My Re is 10000. ------------------------------------------------------------------------------------------------------------------------------------ Here my fvSchemes Code: ```ddtSchemes { default steadyState; } gradSchemes { default Gauss linear; grad(p) Gauss linear; grad(U) Gauss linear; } divSchemes { default none; div(phi,U) Gauss upwind; div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div(phi,nuTilda) Gauss upwind; div((nuEff*dev(grad(U).T()))) Gauss linear; } laplacianSchemes { default none; laplacian(nuEff,U) Gauss linear corrected; laplacian((1|A(U)),p) Gauss linear corrected; laplacian(DkEff,k) Gauss linear corrected; laplacian(DepsilonEff,epsilon) Gauss linear corrected; laplacian(DREff,R) Gauss linear corrected; laplacian(DnuTildaEff,nuTilda) Gauss linear corrected; } interpolationSchemes { default linear; interpolate(U) linear; } snGradSchemes { default corrected; } fluxRequired { default no; p; }``` ------------------------------------------------------------------------------------------------------------------------------------ Now my fvSolution Code: ```solvers { p PCG { preconditioner DIC; tolerance 1e-06; relTol 0.01; }; U PBiCG { preconditioner DILU; tolerance 1e-05; relTol 0.1; }; k PBiCG { preconditioner DILU; tolerance 1e-05; relTol 0.1; }; epsilon PBiCG { preconditioner DILU; tolerance 1e-05; relTol 0.1; }; R PBiCG { preconditioner DILU; tolerance 1e-05; relTol 0.1; }; nuTilda PBiCG { preconditioner DILU; tolerance 1e-05; relTol 0.1; }; } SIMPLE { nNonOrthogonalCorrectors 0; pRefCell 0; pRefValue 0; } relaxationFactors { p 0.3; U 0.75; k 0.7; epsilon 0.7; R 0.7; nuTilda 0.7; }``` ----------------------------------------------------------------------------------------------------------------------------------- Time 0 for U Code: ``` inlet { type fixedValue; value uniform (0 0 3); } wall { type fixedValue; value uniform (0 0 0); } simetria { type symmetryPlane; } outlet { type zeroGradient; }``` --------------------------------------------------------------------------------------------------------------------------------------- Time 0 for p Code: ``` inlet { type zeroGradient; } wall { type zeroGradient; } simetria { type symmetryPlane; } outlet { type fixedValue; value uniform 0; }``` My log file Code: ```Time = 456 DILUPBiCG: Solving for Ux, Initial residual = 0.000512103, Final residual = 1.48703e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000401474, Final residual = 1.10876e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 4.50922e-05, Final residual = 1.18828e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00228803, Final residual = 2.27407e-05, No Iterations 164 time step continuity errors : sum local = 0.00238667, global = -6.0628e-05, cumulative = -0.127041 DILUPBiCG: Solving for epsilon, Initial residual = 0.000388629, Final residual = 4.27324e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00396427, Final residual = 3.75563e-05, No Iterations 2 ExecutionTime = 7063.29 s ClockTime = 7079 s Time = 457 DILUPBiCG: Solving for Ux, Initial residual = 0.00050372, Final residual = 1.48732e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000393417, Final residual = 1.0608e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 5.00215e-05, Final residual = 1.27123e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00226589, Final residual = 2.24865e-05, No Iterations 163 time step continuity errors : sum local = 0.00235924, global = -0.000164009, cumulative = -0.127205 DILUPBiCG: Solving for epsilon, Initial residual = 0.000388612, Final residual = 4.25304e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00397533, Final residual = 3.7655e-05, No Iterations 2 ExecutionTime = 7073.22 s ClockTime = 7089 s Time = 458 DILUPBiCG: Solving for Ux, Initial residual = 0.000504411, Final residual = 1.47415e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000394789, Final residual = 1.04873e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 6.91581e-05, Final residual = 1.54967e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00224121, Final residual = 2.08246e-05, No Iterations 755 time step continuity errors : sum local = 0.00218417, global = 2.1535e-06, cumulative = -0.127203 DILUPBiCG: Solving for epsilon, Initial residual = 0.000388532, Final residual = 4.2453e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00398655, Final residual = 3.77526e-05, No Iterations 2 ExecutionTime = 7102.86 s ClockTime = 7119 s Time = 459 DILUPBiCG: Solving for Ux, Initial residual = 0.000517339, Final residual = 1.54808e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000410883, Final residual = 1.0981e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 6.09888e-05, Final residual = 1.6352e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00229398, Final residual = 2.18083e-05, No Iterations 179 time step continuity errors : sum local = 0.00229149, global = -5.6239e-05, cumulative = -0.127259 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389129, Final residual = 4.23547e-06, No Iterations 2 bounding epsilon, min: -0.178234 max: 364036 average: 10221.9 DILUPBiCG: Solving for k, Initial residual = 0.00399978, Final residual = 3.78724e-05, No Iterations 2 ExecutionTime = 7113.5 s ClockTime = 7130 s Time = 460 DILUPBiCG: Solving for Ux, Initial residual = 0.000483808, Final residual = 1.44835e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000380046, Final residual = 1.13412e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 4.13029e-05, Final residual = 1.19397e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00227407, Final residual = 2.21498e-05, No Iterations 89 time step continuity errors : sum local = 0.00232672, global = 5.68528e-05, cumulative = -0.127202 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389398, Final residual = 4.23249e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00401211, Final residual = 3.79844e-05, No Iterations 2 ExecutionTime = 7120.94 s ClockTime = 7137 s Time = 461 DILUPBiCG: Solving for Ux, Initial residual = 0.00048556, Final residual = 1.45664e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000381206, Final residual = 1.11524e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 4.07961e-05, Final residual = 1.169e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00225496, Final residual = 2.21822e-05, No Iterations 245 time step continuity errors : sum local = 0.00232942, global = 6.41572e-06, cumulative = -0.127196 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389578, Final residual = 4.22086e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00402382, Final residual = 3.80896e-05, No Iterations 2 ExecutionTime = 7133.82 s ClockTime = 7150 s Time = 462 DILUPBiCG: Solving for Ux, Initial residual = 0.000498512, Final residual = 1.45726e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000391302, Final residual = 1.0683e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 5.1133e-05, Final residual = 1.2756e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00224598, Final residual = 2.19644e-05, No Iterations 332 time step continuity errors : sum local = 0.00230557, global = -4.69691e-05, cumulative = -0.127242 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389523, Final residual = 4.20593e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00403516, Final residual = 3.81893e-05, No Iterations 2 ExecutionTime = 7149.37 s ClockTime = 7165 s Time = 463 DILUPBiCG: Solving for Ux, Initial residual = 0.000508548, Final residual = 1.4678e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000398041, Final residual = 1.05333e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 6.0973e-05, Final residual = 1.43804e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00222826, Final residual = 2.12836e-05, No Iterations 99 time step continuity errors : sum local = 0.00223302, global = -0.000169687, cumulative = -0.127412 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389354, Final residual = 4.18671e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00404604, Final residual = 3.82852e-05, No Iterations 2 ExecutionTime = 7157.2 s ClockTime = 7173 s Time = 464 DILUPBiCG: Solving for Ux, Initial residual = 0.000509481, Final residual = 1.44912e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000397803, Final residual = 1.04437e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 7.94906e-05, Final residual = 1.70902e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.0022065, Final residual = 2.19899e-05, No Iterations 622 time step continuity errors : sum local = 0.0023064, global = 6.12007e-06, cumulative = -0.127406 DILUPBiCG: Solving for epsilon, Initial residual = 0.000389208, Final residual = 4.17798e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00405747, Final residual = 3.8384e-05, No Iterations 2 ExecutionTime = 7182.9 s ClockTime = 7199 s Time = 492 DILUPBiCG: Solving for Ux, Initial residual = 0.000463906, Final residual = 1.2439e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000364687, Final residual = 9.88269e-06, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 4.63961e-05, Final residual = 1.13945e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00209672, Final residual = 2.01067e-05, No Iterations 753 time step continuity errors : sum local = 0.00211535, global = -1.14803e-06, cumulative = -0.127467 DILUPBiCG: Solving for epsilon, Initial residual = 0.000393129, Final residual = 3.98323e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00440507, Final residual = 4.15127e-05, No Iterations 2 ExecutionTime = 7625.11 s ClockTime = 7642 s Time = 493 DILUPBiCG: Solving for Ux, Initial residual = 0.000485382, Final residual = 1.26639e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000382994, Final residual = 2.55656e-05, No Iterations 3 DILUPBiCG: Solving for Uz, Initial residual = 7.7196e-05, Final residual = 1.9067e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00216746, Final residual = 2.16433e-05, No Iterations 24 time step continuity errors : sum local = 0.00228078, global = 5.59411e-05, cumulative = -0.127411 DILUPBiCG: Solving for epsilon, Initial residual = 0.000393817, Final residual = 3.99394e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00442006, Final residual = 4.1653e-05, No Iterations 2 ExecutionTime = 7630.39 s ClockTime = 7647 s Time = 494 DILUPBiCG: Solving for Ux, Initial residual = 0.000454229, Final residual = 1.35997e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000355828, Final residual = 1.68204e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 4.73086e-05, Final residual = 1.32974e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00214212, Final residual = 2.09423e-05, No Iterations 131 time step continuity errors : sum local = 0.00220641, global = 0.000105288, cumulative = -0.127306 DILUPBiCG: Solving for epsilon, Initial residual = 0.00039425, Final residual = 3.9975e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00443389, Final residual = 4.17823e-05, No Iterations 2 ExecutionTime = 7638.92 s ClockTime = 7656 s Time = 495 DILUPBiCG: Solving for Ux, Initial residual = 0.000453295, Final residual = 1.3394e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000356429, Final residual = 9.5217e-06, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 3.69828e-05, Final residual = 1.10254e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00212543, Final residual = 2.08334e-05, No Iterations 340 time step continuity errors : sum local = 0.00219434, global = 8.02239e-05, cumulative = -0.127226 DILUPBiCG: Solving for epsilon, Initial residual = 0.00039448, Final residual = 3.99306e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00444701, Final residual = 4.19023e-05, No Iterations 2 ExecutionTime = 7653.89 s ClockTime = 7671 s Time = 496 DILUPBiCG: Solving for Ux, Initial residual = 0.000470975, Final residual = 1.31057e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000368262, Final residual = 9.95087e-06, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 3.66406e-05, Final residual = 1.02858e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00211582, Final residual = 2.01015e-05, No Iterations 18 time step continuity errors : sum local = 0.00211615, global = 7.15807e-05, cumulative = -0.127154 DILUPBiCG: Solving for epsilon, Initial residual = 0.0003944, Final residual = 3.98107e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00445943, Final residual = 4.20142e-05, No Iterations 2 ExecutionTime = 7658.79 s ClockTime = 7676 s Time = 497 DILUPBiCG: Solving for Ux, Initial residual = 0.000469239, Final residual = 1.27665e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000365393, Final residual = 1.34082e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 5.0851e-05, Final residual = 1.24694e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00209146, Final residual = 2.08967e-05, No Iterations 154 time step continuity errors : sum local = 0.00219931, global = -5.47e-05, cumulative = -0.127209 DILUPBiCG: Solving for epsilon, Initial residual = 0.000394246, Final residual = 3.96901e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00447105, Final residual = 4.21189e-05, No Iterations 2 ExecutionTime = 7668.1 s ClockTime = 7685 s Time = 498 DILUPBiCG: Solving for Ux, Initial residual = 0.000474228, Final residual = 1.27292e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000369804, Final residual = 1.17542e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 7.23045e-05, Final residual = 1.57116e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.0020701, Final residual = 2.01235e-05, No Iterations 63 time step continuity errors : sum local = 0.00211732, global = -0.00012504, cumulative = -0.127334 DILUPBiCG: Solving for epsilon, Initial residual = 0.000393942, Final residual = 3.95612e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00448192, Final residual = 4.22152e-05, No Iterations 2 ExecutionTime = 7674.4 s ClockTime = 7691 s Time = 499 DILUPBiCG: Solving for Ux, Initial residual = 0.00047692, Final residual = 1.27242e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000371529, Final residual = 1.15432e-05, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 9.53324e-05, Final residual = 1.94679e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00204754, Final residual = 1.80723e-05, No Iterations 730 time step continuity errors : sum local = 0.00190096, global = -2.64022e-07, cumulative = -0.127334 DILUPBiCG: Solving for epsilon, Initial residual = 0.000393712, Final residual = 3.94621e-06, No Iterations 2 bounding epsilon, min: -0.314136 max: 372313 average: 10397.8 DILUPBiCG: Solving for k, Initial residual = 0.00449351, Final residual = 4.23151e-05, No Iterations 2 ExecutionTime = 7701.85 s ClockTime = 7719 s Time = 500 DILUPBiCG: Solving for Ux, Initial residual = 0.000511951, Final residual = 1.3066e-05, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.000407941, Final residual = 1.0782e-05, No Iterations 3 DILUPBiCG: Solving for Uz, Initial residual = 7.41097e-05, Final residual = 1.99966e-06, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.00213221, Final residual = 2.02643e-05, No Iterations 16 time step continuity errors : sum local = 0.00213662, global = -1.03452e-05, cumulative = -0.127344 DILUPBiCG: Solving for epsilon, Initial residual = 0.000394417, Final residual = 3.95603e-06, No Iterations 2 DILUPBiCG: Solving for k, Initial residual = 0.00450856, Final residual = 4.24534e-05, No Iterations 2 ExecutionTime = 7710.26 s ClockTime = 7727 s``` Last edited by jonmec; June 3, 2011 at 19:05. Reason: Complementation

 June 4, 2011, 09:32 #2 New Member   Jonathas Assunção de Castro Join Date: Mar 2009 Posts: 11 Rep Power: 9 Somedody? Please .... help me =]

 July 27, 2011, 09:55 #3 Senior Member     mauricio Join Date: Jun 2011 Posts: 141 Rep Power: 9 hi jon! i'm new to foam myself but i think you could try coping the system file from the tutorials folder to your case folder (~/tutorials/incompressible/simpleFoam/airFoil2D/system ) and run it with these settings. Make sure u got the right patches and boundary conditions you might wanna try setting some monitor points (can't help you much on this) to make sure your results are converging, check your 'stop" criteria too in controlDic /calim

 July 28, 2011, 05:24 #4 New Member   Balakrshnan Ramakrishnan Join Date: May 2009 Posts: 22 Rep Power: 9 I cannot say from the few lines of your log file, that the solution is not converging.. If you have written out the log file, you can try using tools like PyFoamPlotWatcher to see how the residuals are.

 Tags convergence issues, orifice plate, simplefoam

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