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Air water interface
Posted Mar 14, 2011, 9:27 a.m. EDT Acoustics & Vibrations Version 5.2a 4 Replies
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Hi friends,
I want to solve the "Separation through electrocoalescence" in the model library but with air as a continuum phase. When I changed the material from oil to Air, the similar solver could not solve the problem. I just changed the oil to air in my model and all other settings is the same as in the model library that works with oil.
should i change the solver or the mesh ?
thanks,
I want to solve the "Separation through electrocoalescence" in the model library but with air as a continuum phase. When I changed the material from oil to Air, the similar solver could not solve the problem. I just changed the oil to air in my model and all other settings is the same as in the model library that works with oil.
should i change the solver or the mesh ?
thanks,
4 Replies Last Post Apr 24, 2017, 8:06 p.m. EDT
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Posted:
1 decade ago
Hi
could it be that the physics for air, a gas and oil a liquid are not fully the same, or just that you need to rescale some parameters, for me it's not "just" a small change ;)
But certainly, with some tweaking it should work
--
Good luck
Ivar
could it be that the physics for air, a gas and oil a liquid are not fully the same, or just that you need to rescale some parameters, for me it's not "just" a small change ;)
But certainly, with some tweaking it should work
--
Good luck
Ivar
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Posted:
1 decade ago
hi Ivar,
what do u mean by rescaling ? what parameters should I rescale ?
what do u mean by rescaling ? what parameters should I rescale ?
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Posted:
1 decade ago
Hi
the dependent variables are "scaled" by COMSOL to avoid having some at 1E-12 and others at 1E+12, when you change so drastically air against oil (if I understood you correctly) then COMSOL might not have scaled correctly. One way is to reset the solver (means loosing your Results too, you need to rebuild them). Another way is to turn the detailed log file mode ON and check the scalings values you normally get then in the log. This is just a guess, it might be something completely different ;) Then to plot the dependent variables to see what they result to.
To be sure you understand what is going on, specially when you have doubts about the results, then its important to check all parameters in particular all dependent variables to see how they look
You might then decide to change some initial conditions to look rather like the result, this will allow next sequence to solve quicker (if you do not have any errors)
--
Good luck
Ivar
the dependent variables are "scaled" by COMSOL to avoid having some at 1E-12 and others at 1E+12, when you change so drastically air against oil (if I understood you correctly) then COMSOL might not have scaled correctly. One way is to reset the solver (means loosing your Results too, you need to rebuild them). Another way is to turn the detailed log file mode ON and check the scalings values you normally get then in the log. This is just a guess, it might be something completely different ;) Then to plot the dependent variables to see what they result to.
To be sure you understand what is going on, specially when you have doubts about the results, then its important to check all parameters in particular all dependent variables to see how they look
You might then decide to change some initial conditions to look rather like the result, this will allow next sequence to solve quicker (if you do not have any errors)
--
Good luck
Ivar
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Posted:
8 years ago
Hello,
I want to model ultrasound wave propagation in water. In my domain, I have a solid domain too and the whole computational domain is surrounded by air.
I want to know can I replace the air domain by a boundary condition? If yes, what kind of boundary condition should I use for the water-air and solid-air interface? sound hard boundary or soft boundary?
Thanks,
I want to model ultrasound wave propagation in water. In my domain, I have a solid domain too and the whole computational domain is surrounded by air.
I want to know can I replace the air domain by a boundary condition? If yes, what kind of boundary condition should I use for the water-air and solid-air interface? sound hard boundary or soft boundary?
Thanks,