volume fraction = nan
The liquid phase volume fraction is too large during interDyMFoam run. What should I do?
Thanks, Centre of mass: (3.99998969769 0.199999365532 0.00194121622769) Linear velocity: (0.00807274666396 0.000116891215473 1.22736927321) Angular velocity: (50.7400957943 350.884852997 0.162897658258) Centre of mass: (3.99998969769 0.199999365532 0.00194121622769) Linear velocity: (0.00807274666396 0.000116891215473 1.22736927321) Angular velocity: (50.7400957943 350.884852997 0.162897658258) GAMG: Solving for cellDisplacementx, Initial residual = 1, Final residual = 7.59907279221e06, No Iterations 4 GAMG: Solving for cellDisplacementy, Initial residual = 1, Final residual = 7.48199156032e06, No Iterations 4 GAMG: Solving for cellDisplacementx, Initial residual = 1, Final residual = 7.59907279221e06, No Iterations 4 GAMG: Solving for cellDisplacementz, Initial residual = 1, Final residual = 6.28747292815e06, No Iterations 4 GAMG: Solving for cellDisplacementy, Initial residual = 1, Final residual = 7.48199156032e06, No Iterations 4 GAMG: Solving for cellDisplacementz, Initial residual = 1, Final residual = 6.28747292815e06, No Iterations 4 Execution time for mesh.update() = 14.83 s time step continuity errors : sum local = 4.34625791759e11, global = 2.0984282934e13, cumulative = 4.55449681311e06 Execution time for mesh.update() = 14.84 s time step continuity errors : sum local = 4.34625791759e11, global = 2.0984282934e13, cumulative = 4.55449681311e06 GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 7.16391976148e06, No Iterations 8 time step continuity errors : sum local = 3.11362494258e16, global = 5.34853518262e18, cumulative = 4.55449681311e06 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 1.44928608738e+296 Max(alpha1) = 1.18486320879e+296 GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 7.16391976148e06, No Iterations 8 time step continuity errors : sum local = 3.11362494258e16, global = 5.34853518262e18, cumulative = 4.55449681311e06 MULES: Solving for alpha1 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 9067.86973555 Max(alpha1) = 873794.676324 Liquid phase volume fraction = nan Min(alpha1) = 1.44928608738e+296 Max(alpha1) = 1.18486320879e+296 MULES: Solving for alpha1 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 21395657433.6 Max(alpha1) = 3942543.65753 Liquid phase volume fraction = nan Min(alpha1) = 9067.86973555 Max(alpha1) = 873794.676324 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 21395657433.6 Max(alpha1) = 3942543.65753 
after reducing timestep, tried both GAMGPCG and DICPCG for solving pcorr and still cannot fix this. solution gives singularity when solving pcorr.
Centre of mass: (1.50001686526 0.499972308524 0.493779071806) Linear velocity: (0.00249152243223 0.00491296145985 0.845915059591) Angular velocity: (8.1941654618 6.9633990245 0.737810296966) Centre of mass: (1.50001686526 0.499972308524 0.493779071806) Linear velocity: (0.00249152243223 0.00491296145985 0.845915059591) Angular velocity: (8.1941654618 6.9633990245 0.737810296966) GAMG: Solving for cellDisplacementx, Initial residual = 1, Final residual = 3.96337485906e06, No Iterations 6 GAMG: Solving for cellDisplacementx, Initial residual = 1, Final residual = 3.96337485906e06, No Iterations 6 GAMG: Solving for cellDisplacementy, Initial residual = 1, Final residual = 3.72427537902e06, No Iterations 6 GAMG: Solving for cellDisplacementy, Initial residual = 1, Final residual = 3.72427537902e06, No Iterations 6 GAMG: Solving for cellDisplacementz, Initial residual = 1, Final residual = 8.96207859635e06, No Iterations 6 GAMG: Solving for cellDisplacementz, Initial residual = 1, Final residual = 8.96207859635e06, No Iterations 6 Execution time for mesh.update() = 17.76 s time step continuity errors : sum local = 1.01648889068e10, global = 3.98753833131e12, cumulative = 6.73971151269e09 Execution time for mesh.update() = 17.74 s time step continuity errors : sum local = 1.01648889068e10, global = 3.98753833131e12, cumulative = 6.73971151269e09 DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 9.96719754608e07, No Iterations 255 DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 9.96719754608e07, No Iterations 255 DICPCG: Solving for pcorr: solution singularity DICPCG: Solving for pcorr: solution singularity DICPCG: Solving for pcorr: solution singularity time step continuity errors : sum local = inf, global = inf, cumulative = inf DICPCG: Solving for pcorr: solution singularity time step continuity errors : sum local = inf, global = inf, cumulative = inf MULES: Solving for alpha1 MULES: Solving for alpha1 Liquid phase volume fraction = inf Min(alpha1) = inf Max(alpha1) = 1.83985404514e+287 Liquid phase volume fraction = inf Min(alpha1) = inf Max(alpha1) = 1.83985404514e+287 MULES: Solving for alpha1 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 52.2330190268 Max(alpha1) = 29.9036740755 Liquid phase volume fraction = nan Min(alpha1) = 52.2330190268 Max(alpha1) = 29.9036740755 MULES: Solving for alpha1 MULES: Solving for alpha1 Liquid phase volume fraction = nan Min(alpha1) = 504.821905808 Max(alpha1) = 387.19735435 Liquid phase volume fraction = nan Min(alpha1) = 504.821905808 Max(alpha1) = 387.19735435 
At timestep=0, it works fine but iteration blows up at next timestep. DT=0.005s. I am posting a link to the image at t=0.
http://www.cfdonline.com/Forums/mem...imestep0.html Thank you for any response. 
Hi VirtualiCFD,
I only have a very limited understanding of how interFoam and interDyMFoam work, but basically here's what could be wrong:
Best regards, Bruno 
Hi Bruno, thank you for your prompt response.
After reducing deltaT from 0.005s to 0.0025s and now I checkMesh the geometry and the new mesh now has some problems. I will try to fix it and post the progress here. Create time Create polyMesh for time = 0 Time = 0 Mesh stats points: 767593 faces: 2204098 internal faces: 2137246 cells: 719444 boundary patches: 6 point zones: 0 face zones: 0 cell zones: 0 Overall number of cells of each type: hexahedra: 701651 prisms: 3585 wedges: 0 pyramids: 0 tet wedges: 32 tetrahedra: 0 polyhedra: 14176 Checking topology... Boundary definition OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces ... Patch Faces Points Surface topology sidewall 20480 20930 ok (nonclosed singly connected) inlet 4096 4225 ok (nonclosed singly connected) outlet 4096 4225 ok (nonclosed singly connected) floor 10240 10465 ok (nonclosed singly connected) ceiling 10240 10465 ok (nonclosed singly connected) floatingObject 17700 19883 ok (closed singly connected) Checking geometry... Overall domain bounding box (4 2 3) (8 3 4) Mesh (nonempty, nonwedge) directions (1 1 1) Mesh (nonempty) directions (1 1 1) Boundary openness (7.93596913354e16 2.25264336087e16 1.5514796242e15) OK. Max cell openness = 3.04515531184e16 OK. Max aspect ratio = 4.39517096183 OK. Minumum face area = 4.29684081531e05. Maximum face area = 0.0085458594. Face area magnitudes OK. Min volume = 1.240235887e06. Max volume = 0.000640939455. Total volume = 418.630237694. Cell volumes OK. Mesh nonorthogonality Max: 55.9891415978 average: 3.848649819 Nonorthogonality check OK. Face pyramids OK. Max skewness = 2.29577137119 OK. Mesh OK. Time = 0.005 Checking geometry... Overall domain bounding box (4 2 3) (8 3 4) Mesh (nonempty, nonwedge) directions (1 1 1) Mesh (nonempty) directions (1 1 1) Boundary openness (7.83532651411e16 2.26932595494e16 1.54953377682e15) OK. Max cell openness = 4.32512283352e16 OK. Max aspect ratio = 4.20723431263 OK. Minumum face area = 4.2968408155e05. Maximum face area = 0.00893658472989. Face area magnitudes OK. Min volume = 1.22476329522e06. Max volume = 0.000668814291826. Total volume = 418.630237804. Cell volumes OK. Mesh nonorthogonality Max: 58.6431968444 average: 3.90508611734 Nonorthogonality check OK. ***Error in face pyramids: 3 faces are incorrectly oriented. <<Writing 3 faces with incorrect orientation to set wrongOrientedFaces Max skewness = 2.32252294916 OK. Failed 1 mesh checks. End 
Your time step might still be too large. I'd aim for a maximum Courant number of 0.2 (deltaT = 1e05 maybe? depends on your setup, which you have told us nothing about), and from there increase the time step a bit if it runs smoothly.

Hi Anton,
I greatly appreciate your reply. In fact, I have stopped working on this case due to its complex geometry to begin with and after several failed attempts over the last weekend. In fact, I've just started with a much simpler and different geometry mesh to see if I can get over with this issue. As you see from my log message below, now I encountered difficulty as my timestep is getting smaller and smaller. I've posted some setting for the information. http://www.cfdonline.com/Forums/ope...nonstop.html I will try lower Co number at 0.2 and let you know the progress. 
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