Hello Edgaras
                            
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                                                Posted:
                            
                                9 years ago                            
                            
                                12 sept. 2016, 01:17 UTC−4                            
                        
                        
                                                    Does anyone encounter the same problem and have experience about it? If the "form assembly" is selected in last step in geometry setup, the fluid-solid interaction entity is not available, the fluid-solid boundary is not applicable if you choose them.                                                 
                                                
                            Does anyone encounter the same problem and have experience about it? If the "form assembly" is selected in last step in geometry setup, the fluid-solid interaction entity is not available, the fluid-solid boundary is not applicable if you choose them.                         
                                                
                                                                                                            
                                             
                                            
                            
                                                                                        
                                Nagi Elabbasi
                                                                                                                                                    Facebook Reality Labs
                                                         
                            
                         
                                                
    
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                                                Posted:
                            
                                9 years ago                            
                            
                                13 sept. 2016, 13:26 UTC−4                            
                        
                        
                                                    Hi Zeng,
The fluid-structure boundary automatically detected by COMSOL requires a unioned geometry, I believe. COMSOL detects if you have a solid at one side and a fluid at the other side of the same surface (line in 2D), and creates the FSI boundary. If there is contact as in the case Edgaras described above you can add a Union operation before the final Assembly to connect the domains that make up the FSI boundary.
Nagi Elabbasi
Veryst Engineering                                                
                                                
                            Hi Zeng,
The fluid-structure boundary automatically detected by COMSOL requires a unioned geometry, I believe. COMSOL detects if you have a solid at one side and a fluid at the other side of the same surface (line in 2D), and creates the FSI boundary. If there is contact as in the case Edgaras described above you can add a Union operation before the final Assembly to connect the domains that make up the FSI boundary.
Nagi Elabbasi
Veryst Engineering                        
                                                
                                                                                                            
                                             
                        
                        
                                                
    
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                                                Posted:
                            
                                9 years ago                            
                            
                                15 sept. 2016, 00:21 UTC−4                            
                        
                        
                                                    Dear Nagi,
Thanks a lot for your suggestion. I followed your advice and set up a simple model to implement it. stack three rectangular vertically. and suppose the intermediate rectangular denotes the fluid domain, and upper and lower two rectangular denotes solid domains. With "Union" before "form assembly", the upper fluid-solid interface is applicable to FSI tab, but for the lower fluid-solid interface, it's still not applicable to FSI. For this sample, can you give me some idea about it?
Thanks for your any comments.
Zeng                                                 
                                                
                            Dear Nagi,
Thanks a lot for your suggestion. I followed your advice and set up a simple model to implement it. stack three rectangular vertically. and suppose the intermediate rectangular denotes the fluid domain, and upper and lower two rectangular denotes solid domains. With "Union" before "form assembly", the upper fluid-solid interface is applicable to FSI tab, but for the lower fluid-solid interface, it's still not applicable to FSI. For this sample, can you give me some idea about it?
Thanks for your any comments.
Zeng