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July 13, 2015, 10:11 
Problem with complex eigenValues

#1 
Member
Join Date: Dec 2014
Posts: 50
Rep Power: 4 
Hey,
Using the icoFsiElasticNonLinULSolidFoam solver to simulate beam deformation due to some kind of fluid (resin) I get the following problem with complex eigenValues. Code:
Create time Create dynamic mesh for time = 0 Selecting dynamicFvMesh dynamicMotionSolverFvMesh Selecting motion solver: laplace Selecting motion diffusivity: quadratic Reading transportProperties Reading field p Reading field U Reading/calculating face flux field phi Reading incremental displacement field DU Patch consoleSolid Traction boundary field: DU nonLinear set to updated Lagrangian Reading incremental displacement field DV Reading accumulated velocity field V Reading accumulated stress field sigma Reading incremental stress field DSigma Selecting rheology model linearElastic Creating constitutive model Reading coupling properties Create fluidtosolid and solidtofluid interpolators Check fluidtosolid and solidtofluid interpolators Fluidtosolid face interpolation error: 0.010148376 Solidtofluid face interpolation error: 0.01019123 Starting time loop Time = 0.001 Selecting coupling scheme Aitken Time = 0.001, iteration: 1 Current fsi underrelaxation factor: 0.01 Maximal accumulated displacement of interface points: 0 Courant Number mean: 0 max: 0 velocity magnitude: 0 DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 8.3132673e07, No Iterations 18 DILUPBiCG: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0 DILUPBiCG: Solving for Uz, Initial residual = 0, Final residual = 0, No Iterations 0 GAMG: Solving for p, Initial residual = 1, Final residual = 8.4510406e07, No Iterations 31 GAMG: Solving for p, Initial residual = 0.11197892, Final residual = 4.9492681e07, No Iterations 23 GAMG: Solving for p, Initial residual = 0.019307684, Final residual = 5.7220616e07, No Iterations 19 GAMG: Solving for p, Initial residual = 0.0051776203, Final residual = 8.4609257e07, No Iterations 13 GAMG: Solving for p, Initial residual = 0.0018300923, Final residual = 9.1210219e07, No Iterations 9 GAMG: Solving for p, Initial residual = 0.00066812399, Final residual = 6.8161564e07, No Iterations 7 time step continuity errors : sum local = 1.2555142e08, global = 2.3714846e10, cumulative = 2.3714846e10 GAMG: Solving for p, Initial residual = 0.53146611, Final residual = 5.978844e07, No Iterations 29 GAMG: Solving for p, Initial residual = 0.20182154, Final residual = 9.9028612e07, No Iterations 24 GAMG: Solving for p, Initial residual = 0.042800682, Final residual = 5.2895856e07, No Iterations 21 GAMG: Solving for p, Initial residual = 0.011775962, Final residual = 9.6208771e07, No Iterations 15 GAMG: Solving for p, Initial residual = 0.0041584696, Final residual = 4.5080195e07, No Iterations 13 GAMG: Solving for p, Initial residual = 0.0015133582, Final residual = 7.2392118e07, No Iterations 8 time step continuity errors : sum local = 5.5095195e09, global = 2.1325662e10, cumulative = 2.3891839e11 GAMG: Solving for p, Initial residual = 0.29927741, Final residual = 9.4244826e07, No Iterations 24 GAMG: Solving for p, Initial residual = 0.012474404, Final residual = 9.8173954e07, No Iterations 16 GAMG: Solving for p, Initial residual = 0.0021021264, Final residual = 9.130113e07, No Iterations 10 GAMG: Solving for p, Initial residual = 0.00060303569, Final residual = 7.4261747e07, No Iterations 7 GAMG: Solving for p, Initial residual = 0.00022272133, Final residual = 5.699134e07, No Iterations 6 GAMG: Solving for p, Initial residual = 8.4422059e05, Final residual = 4.7794747e07, No Iterations 5 time step continuity errors : sum local = 2.4638291e09, global = 9.6306776e11, cumulative = 7.2414937e11 GAMG: Solving for p, Initial residual = 0.15397893, Final residual = 4.9561848e07, No Iterations 21 GAMG: Solving for p, Initial residual = 0.0040461499, Final residual = 8.909345e07, No Iterations 12 GAMG: Solving for p, Initial residual = 0.00060316435, Final residual = 7.2521584e07, No Iterations 6 GAMG: Solving for p, Initial residual = 0.00015816922, Final residual = 8.635744e07, No Iterations 5 GAMG: Solving for p, Initial residual = 5.5933466e05, Final residual = 6.7512527e07, No Iterations 4 GAMG: Solving for p, Initial residual = 2.0009206e05, Final residual = 7.0327084e07, No Iterations 3 time step continuity errors : sum local = 3.0437577e09, global = 5.0514774e11, cumulative = 1.2292971e10 GAMG: Solving for p, Initial residual = 0.09966961, Final residual = 7.9882574e07, No Iterations 19 GAMG: Solving for p, Initial residual = 0.0021026035, Final residual = 7.7451051e07, No Iterations 11 GAMG: Solving for p, Initial residual = 0.0003114969, Final residual = 8.0088546e07, No Iterations 6 GAMG: Solving for p, Initial residual = 7.9168706e05, Final residual = 4.1457659e07, No Iterations 5 GAMG: Solving for p, Initial residual = 2.7196661e05, Final residual = 4.5421346e07, No Iterations 4 GAMG: Solving for p, Initial residual = 9.7404879e06, Final residual = 9.6395309e07, No Iterations 2 time step continuity errors : sum local = 3.742613e09, global = 3.7893867e11, cumulative = 1.6082358e10 GAMG: Solving for p, Initial residual = 0.067709768, Final residual = 3.3787923e07, No Iterations 19 GAMG: Solving for p, Initial residual = 0.001238497, Final residual = 6.5694878e07, No Iterations 9 GAMG: Solving for p, Initial residual = 0.00018346641, Final residual = 9.203233e07, No Iterations 5 GAMG: Solving for p, Initial residual = 4.7386527e05, Final residual = 5.6317931e07, No Iterations 4 GAMG: Solving for p, Initial residual = 1.6343804e05, Final residual = 6.4763955e07, No Iterations 3 GAMG: Solving for p, Initial residual = 6.0068916e06, Final residual = 6.3302699e07, No Iterations 2 time step continuity errors : sum local = 2.2796623e09, global = 4.0342121e11, cumulative = 2.011657e10 GAMG: Solving for p, Initial residual = 0.049479011, Final residual = 4.0133808e07, No Iterations 19 GAMG: Solving for p, Initial residual = 0.0008968961, Final residual = 9.4596208e07, No Iterations 8 GAMG: Solving for p, Initial residual = 0.00014130527, Final residual = 8.4796864e07, No Iterations 5 GAMG: Solving for p, Initial residual = 3.7615407e05, Final residual = 4.6315112e07, No Iterations 4 GAMG: Solving for p, Initial residual = 1.3117843e05, Final residual = 5.2243324e07, No Iterations 3 GAMG: Solving for p, Initial residual = 4.9612375e06, Final residual = 5.3065942e07, No Iterations 2 time step continuity errors : sum local = 1.8024859e09, global = 3.4321021e11, cumulative = 2.3548672e10 GAMG: Solving for p, Initial residual = 0.037470098, Final residual = 9.1049378e07, No Iterations 17 GAMG: Solving for p, Initial residual = 0.00062369277, Final residual = 7.6589462e07, No Iterations 7 GAMG: Solving for p, Initial residual = 9.851143e05, Final residual = 5.9136462e07, No Iterations 5 GAMG: Solving for p, Initial residual = 2.55739e05, Final residual = 7.3420652e07, No Iterations 3 GAMG: Solving for p, Initial residual = 9.0831531e06, Final residual = 8.9706984e07, No Iterations 2 GAMG: Solving for p, Initial residual = 3.539342e06, Final residual = 4.1343948e07, No Iterations 2 time step continuity errors : sum local = 1.3410325e09, global = 4.1947225e11, cumulative = 2.7743395e10 GAMG: Solving for p, Initial residual = 0.029567073, Final residual = 8.7894614e07, No Iterations 17 GAMG: Solving for p, Initial residual = 0.00049695739, Final residual = 7.2217496e07, No Iterations 7 GAMG: Solving for p, Initial residual = 8.0604414e05, Final residual = 5.182067e07, No Iterations 5 GAMG: Solving for p, Initial residual = 2.2075999e05, Final residual = 7.3302099e07, No Iterations 3 GAMG: Solving for p, Initial residual = 7.8158024e06, Final residual = 8.0647039e07, No Iterations 2 GAMG: Solving for p, Initial residual = 3.162127e06, Final residual = 9.8778579e07, No Iterations 1 time step continuity errors : sum local = 3.0850137e09, global = 3.9143509e11, cumulative = 3.1657745e10 GAMG: Solving for p, Initial residual = 0.02352783, Final residual = 7.2779874e07, No Iterations 17 GAMG: Solving for p, Initial residual = 0.00037960579, Final residual = 7.6354505e07, No Iterations 6 GAMG: Solving for p, Initial residual = 6.1634295e05, Final residual = 4.0162528e07, No Iterations 5 GAMG: Solving for p, Initial residual = 1.630773e05, Final residual = 4.8443595e07, No Iterations 3 GAMG: Solving for p, Initial residual = 5.7762329e06, Final residual = 5.7300479e07, No Iterations 2 GAMG: Solving for p, Initial residual = 2.2465927e06, Final residual = 6.8744055e07, No Iterations 1 time step continuity errors : sum local = 2.0815317e09, global = 3.8350853e11, cumulative = 3.5492831e10 Setting traction on solid patch Total traction force = (9.5242657e11 3.677489e12 7.535462e10) > FOAM Warning : From function eigenValues(const tensor&) in file primitives/Tensor/tensor/tensor.C at line 170 complex eigenvalues detected for tensor: (9177.5336 1.619439e05 0.012441039 94407.607 82602.655 7.4239701e+08 74434408 62320794 5.8801867e+11) . . . . . > FOAM Warning : From function eigenValues(const tensor&) in file primitives/Tensor/tensor/tensor.C at line 170 complex eigenvalues detected for tensor: (5.5240793e+21 0 0 5.9533364e+32 4.9617278e+32 4.6815738e+36 3.2393035e+35 2.6998181e+35 2.5473779e+39) Floating point exception (core dumped) I already read the tensor.C file trying to understand it but I'm not that good in C++ :/ Maybe the solution for my problem is given there and I'm just incapable to get it ' Could you guys please help me? I'm stuck with this for days now Every suggestion is very welcomed 

July 14, 2015, 02:31 

#2 
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Join Date: Jan 2015
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I think that no one find a solution for this problem... I'm also searching for solution but without success. foamextend is not wellsupported by community.


July 20, 2015, 08:36 

#3 
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Join Date: Dec 2014
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July 21, 2015, 01:19 

#4 
Senior Member
Join Date: Jan 2015
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Yes, I have this problem too and I don't find a solution for it...


August 3, 2015, 10:38 

#5 
New Member
rasool soofi nooghabi
Join Date: Mar 2015
Posts: 16
Rep Power: 4 
hi
can you find a solution for this problem ? I have this problem, too thank you 

August 4, 2015, 08:38 

#6  
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Join Date: Dec 2014
Posts: 50
Rep Power: 4 
Quote:
Yes, actually I found my problem. It was due to a false numbering of the blocks with hex (). The User's Guide says: Quote:
Hope, it helps for you.. 

November 2, 2015, 11:18 

#7  
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Join Date: Dec 2014
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Svensen:
Quote:
Quote:


November 16, 2015, 02:36 

#8 
New Member
rasool soofi nooghabi
Join Date: Mar 2015
Posts: 16
Rep Power: 4 
hi
yes ,i have this problem yet i am using icofsinonlinulsolidfoam sover from foamextend 3.1 when i run my case with geometry scale of 200 and time step of 0.01 i dont have this problem but when i run my case with geometry scale of 1 and time step of 0.000001 this problem occur and stop my solution . courant number during solution is low. myfsi.log file 

November 17, 2015, 03:18 

#9 
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rasool soofi nooghabi
Join Date: Mar 2015
Posts: 16
Rep Power: 4 
thank you harak !
my case geometery generated by gambit . what means (right handed coordinate ...) in gambit mesh ?? 

November 21, 2015, 04:22 

#10 
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Join Date: Dec 2014
Posts: 50
Rep Power: 4 
Hi Rasool,
sorry for the late answer. However, I assume that this problem occurs at your case because you're using a third party mesh generation tool. The solver icofsinonlinulsolidfoam needs a 1:1 face match between the fluid and the solid patch. I'm pretty sure that your mesh isn't considering this fact. Try using blockMesh for your geometry I hope your geometry isn't that complicated And please let me know if this is working for you. 

November 24, 2015, 06:01 

#11 
Senior Member
Join Date: Jan 2015
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Does anyone find a solution ?


January 26, 2016, 02:48 

#12 
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Join Date: Jan 2015
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Does anyone found a solution ?


Tags 
complex eigenvalues, fluid structure, fsi 
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