[Seervan]

Greetings all
At first I gotta say that I am well aware of the tutorial of KCS Resistance test and when I have done it, nothing was wrong. So here is the case:
I try to model the exact problem with other vessels but when I try to capture the wave patterns, things go nasty and it doesn't seem right and I think its because of the mesh. The tutorial is great but it doesn't give u the solid idea about how exactly you do the meshing. I tried to play the same macro and techniques in the tutorial on a KVLCC2 model and even have scaled down the numbers so they fit to the model. but after about 13s of solution time, the wave pattern becomes ridiculous.
even the mesh I have constructed contains much more cells like in the tutorial everything is fine with almost 500k cells which in my mesh are about 800k.
Any helps would be gladly appreciated.

[Seervan]

Originally Posted by Seervan

Greetings all
At first I gotta say that I am well aware of the tutorial of KCS Resistance test and when I have done it, nothing was wrong. So here is the case:
I try to model the exact problem with other vessels but when I try to capture the wave patterns, things go nasty and it doesn't seem right and I think its because of the mesh. The tutorial is great but it doesn't give u the solid idea about how exactly you do the meshing. I tried to play the same macro and techniques in the tutorial on a KVLCC2 model and even have scaled down the numbers so they fit to the model. but after about 13s of solution time, the wave pattern becomes ridiculous.
even the mesh I have constructed contains much more cells like in the tutorial everything is fine with almost 500k cells which in my mesh are about 800k.
Any helps would be gladly appreciated.

Anyone who needs this, I figured it out my self. So im writing it for further information, so I hope it become handy.
The problem was with the mesh and prism layers simultaneously. At first I stumbled upon the prism layer which was too narrow coz I thought that by narrowing it, mesh resolution would improve. So I decided to thicken it in an order of neighboring cells, so a consistent and eye catching boundary-layer type mesh constructed.
After that I tried to play around the control parameters for the volumetric controls which I had created to adjust the mesh size on the free surface and by scaling down a bit (like from 200% to 100% for trimmer mesh in different directions) and doing a few extra runs (which took 2 more days!) I figured the adequate mesh size.
I know that I have answered to my own question but my aim was to give a guid to anyone who stumbles upon such problem.

[mateusfarah]

I hope that tou could've reached your goal I want to ask If you could help me with my simulation in predicting the resistance of a ship (from the Serie60) using a single phase solver.

The Idea is to use potentialfreesurfacefoam to evaluate the wave resistance and simpleFoam to evaluate the friccional and pressure viscous parcels.

If this Idea is not good I could return to try doing the multiphase simulation with interFoam, using a VOF method to track the freesurface, but I would like to see to see your opinion.

If you prefer you can send me a email for mateusfarah@gmail.com, I would really appreciate your help!

[zyfsoton]

Originally Posted by mateusfarah

I hope that tou could've reached your goal I want to ask If you could help me with my simulation in predicting the resistance of a ship (from the Serie60) using a single phase solver.

The Idea is to use potentialfreesurfacefoam to evaluate the wave resistance and simpleFoam to evaluate the friccional and pressure viscous parcels.

If this Idea is not good I could return to try doing the multiphase simulation with interFoam, using a VOF method to track the freesurface, but I would like to see to see your opinion.

If you prefer you can send me a email for mateusfarah@gmail.com, I would really appreciate your help!

Hi Mateus,

Have you managed to use potentialfreesurfacefoam to compute wave resistance? I am using same solvers to calculate ship resistance, wave patterns etc problems. Any further discussion will be appreciated!

Many thanks
Tony

[mateusfarah]

Originally Posted by zyfsoton

Hi Mateus,

Have you managed to use potentialfreesurfacefoam to compute wave resistance? I am using same solvers to calculate ship resistance, wave patterns etc problems. Any further discussion will be appreciated!

Many thanks
Tony

I had to stop doing simulation to write my paper about the thigns that I have done yet.
I pretend to continue the use of potentialFreeSurfaceFoam to predict the wave resistance in the begining of 2021, than I can reply here the results of my attempts.

If you achieve any progress please return to me, I would appreciate to discuss about that.

[zyfsoton]

Originally Posted by mateusfarah

I had to stop doing simulation to write my paper about the thigns that I have done yet.
I pretend to continue the use of potentialFreeSurfaceFoam to predict the wave resistance in the begining of 2021, than I can reply here the results of my attempts.

If you achieve any progress please return to me, I would appreciate to discuss about that.

Thank you for your quick reply Mateus.

Basically, I have used simpleFoam (for JBC) and interFoam (DTChull)to compute ship resistance (total and frictional resistance). Currently, I am thinking to use potentialfreesurfacefoam to calculate resistance and then make comparison becoz it should be much quicker than multiphase solver. Did you have any potentialfreesurfacefoam tutorial about ship or hull case? Because I cannot find too much related material about this single-phase foam, so it is very hard to start with? I am using OF version6 btw and only tutorial about this solver is oscilatingBox.

Please let me know if you have anything want to share or talk! And my email is zyf277258575@gmail.com

Best regards,
Tony

[Aeronautics El. K.]

Originally Posted by mateusfarah

I hope that tou could've reached your goal I want to ask If you could help me with my simulation in predicting the resistance of a ship (from the Serie60) using a single phase solver.

The Idea is to use potentialfreesurfacefoam to evaluate the wave resistance and simpleFoam to evaluate the friccional and pressure viscous parcels.

If this Idea is not good I could return to try doing the multiphase simulation with interFoam, using a VOF method to track the freesurface, but I would like to see to see your opinion.

If you prefer you can send me a email for mateusfarah@gmail.com, I would really appreciate your help!

Originally Posted by zyfsoton

Hi Mateus,

Have you managed to use potentialfreesurfacefoam to compute wave resistance? I am using same solvers to calculate ship resistance, wave patterns etc problems. Any further discussion will be appreciated!

Many thanks
Tony

Originally Posted by mateusfarah

I had to stop doing simulation to write my paper about the thigns that I have done yet.
I pretend to continue the use of potentialFreeSurfaceFoam to predict the wave resistance in the begining of 2021, than I can reply here the results of my attempts.

If you achieve any progress please return to me, I would appreciate to discuss about that.

Originally Posted by zyfsoton

Thank you for your quick reply Mateus.

Basically, I have used simpleFoam (for JBC) and interFoam (DTChull)to compute ship resistance (total and frictional resistance). Currently, I am thinking to use potentialfreesurfacefoam to calculate resistance and then make comparison becoz it should be much quicker than multiphase solver. Did you have any potentialfreesurfacefoam tutorial about ship or hull case? Because I cannot find too much related material about this single-phase foam, so it is very hard to start with? I am using OF version6 btw and only tutorial about this solver is oscilatingBox.

Please let me know if you have anything want to share or talk! And my email is zyf277258575@gmail.com

Best regards,
Tony

Perhaps this conversation would be more appropriate/suitable in the OpenFOAM section of the forum instead of the STAR-CCM+?