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FSI - High convergence problem
Posted 17.12.2013, 05:30 GMT-5 Studies & Solvers Version 4.3b 2 Replies
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Hi all,
I'm new to COMSOL and I have a problem that involves an interaction between air and a solid body. I am interested in the torque generated on the body by the moving fluid. My intent is to use the interpolation of the torque data obtained for different angular positions of the body, in another model to see how that solid body rotates under that torque conditions. Briefly, I have a rotor in a fluid and I divided my problem into 2 parts.
While trying to obtain the torque applied on the body for its certain angular position, I'm having difficulty in solution, probably due to solver setup. But it can be because of my FSI model if I forgot to add something necessary. Solution takes very long time beacuse of large convergence. If I increase the relative error the convergence decreases but I have to increase the relative error so much for a reasonable computing time. What else I can do? Any suggestion, advice would be appreciated.
A very simple model is attached to illustrate what I'm trying to do.
Thanks in advance,
Utku
I'm new to COMSOL and I have a problem that involves an interaction between air and a solid body. I am interested in the torque generated on the body by the moving fluid. My intent is to use the interpolation of the torque data obtained for different angular positions of the body, in another model to see how that solid body rotates under that torque conditions. Briefly, I have a rotor in a fluid and I divided my problem into 2 parts.
While trying to obtain the torque applied on the body for its certain angular position, I'm having difficulty in solution, probably due to solver setup. But it can be because of my FSI model if I forgot to add something necessary. Solution takes very long time beacuse of large convergence. If I increase the relative error the convergence decreases but I have to increase the relative error so much for a reasonable computing time. What else I can do? Any suggestion, advice would be appreciated.
A very simple model is attached to illustrate what I'm trying to do.
Thanks in advance,
Utku
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2 Replies Last Post 19.12.2013, 07:20 GMT-5
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Posted:
1 decade ago
Try using a fully coupled solver. It is frequently faster than a segregated solver for 2D problems. You also need a finer mesh for the fluid at the narrow constrictions to the left and right of the structure.
Nagi Elabbasi
Veryst Engineering
Nagi Elabbasi
Veryst Engineering
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Posted:
1 decade ago
Dear Nagi,
Thank you for your point, I changed it into fully coupled problem which have decreased the computing time. Also after your comment I noticed that, since solid body will be a rotating structure in reality, those narrow constrictions which increase computing time, are not necessary. Fluid accelerates at those regions because the the solid is static which is not true indeed. After I get rid of those regions, computing time decreased drastically.
Thank you!
Thank you for your point, I changed it into fully coupled problem which have decreased the computing time. Also after your comment I noticed that, since solid body will be a rotating structure in reality, those narrow constrictions which increase computing time, are not necessary. Fluid accelerates at those regions because the the solid is static which is not true indeed. After I get rid of those regions, computing time decreased drastically.
Thank you!