Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                17.01.2011, 09:36 GMT-5                            
                        
                        
                                                    Hi
I believe with a FSI (fluide structure interaction) module it should work :
model the water & the ball (ideally starting inside the water, as if not you need to try special tricks à la "level set", not even sure it works). You add some body load from gravity, use a time series/transient solver, that should be it
probably you could start in 2D-axi to make the model simpler and quicker so solve.
Note, improve somewhat the default initial condition = 0, that helps a lot on the solving time and convergence chances
And use if possible v4.1 it has a better documentation and is smoother than the early version 4.0, particularly for cfd
--
Good luck
Ivar                                                
                                                
                            Hi
I believe with a FSI (fluide structure interaction) module it should work :
model the water & the ball (ideally starting inside the water, as if not you need to try special tricks à la "level set", not even sure it works). You add some body load from gravity, use a time series/transient solver, that should be it
probably you could start in 2D-axi to make the model simpler and quicker so solve.
Note, improve somewhat the default initial condition = 0, that helps a lot on the solving time and convergence chances
And use if possible v4.1 it has a better documentation and is smoother than the early version 4.0, particularly for cfd
--
Good luck
Ivar                        
                                                
                                                                                                            
                                             
                                            
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                17.01.2011, 09:46 GMT-5                            
                        
                        
                                                    Thanks a lot for your reply.
is it possible to model surface between air and water ? I'm new to Comsol. would you please describe more?
I have attached the simple model. I am eager to see surface change during the process.
Gray : Air
Green : Ball
Blue : Water
Thanks                                                
                                                
                            Thanks a lot for your reply.
is it possible to model surface between air and water ? I'm new to Comsol. would you please describe more?
I have attached the simple model. I am eager to see surface change during the process.
Gray : Air
Green : Ball
Blue : Water
Thanks                        
                                                
                        
                                                
                                                                                                            
                                             
                        
                        
                            
                                                                                        
                                Ivar KJELBERG
                                                                                                                                                    COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
                                                         
                            
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                17.01.2011, 09:53 GMT-5                            
                        
                        
                                                    Hi
certainly possible, but that's the trickyest example, i.e. how to define the contact and change in topology ? probably one need to try with a level set methode, but it means formula tweaking, and fun, but too much to do for now and here, for me :) 
Sorry cannot do better, but try already a falling ball in a tube of water, once you have that running, you should also have some good clues how to continue
--
Good luck
Ivar                                                
                                                
                            Hi
certainly possible, but that's the trickyest example, i.e. how to define the contact and change in topology ? probably one need to try with a level set methode, but it means formula tweaking, and fun, but too much to do for now and here, for me :) 
Sorry cannot do better, but try already a falling ball in a tube of water, once you have that running, you should also have some good clues how to continue
--
Good luck
Ivar