Learning Forum

[Noah Fournier]

I have a two-way FSI set up with system coupling using Transient structural and Fluent. The simulation runs fine but I found out after reviewing the results that Fluent sends the force calculated from the STATIC pressure component only to the system coupling. This is very bad in my case because I have a compressible fluid (air ideal gas) which is flowing at high speeds (mach 2 in some spots) so the force due to dynamic pressure needs to be accounted for as well. The only information I found on this is from this post about a year ago where it seems like ANSYS developers knew this is a problem (/forum/forums/topic/fsi-problem-importing-pressures-from-fluent-to-static-structural/) . Has anyone found a work around to this yet???? Is there any way to change how FLuent is calculating this force? 

[Rahul]

Which version are you using? The issue mentioned in that post is corrected in latest version.

Whether fluid and solid interfaces are mapped correctly?

[Noah Fournier]

 

I am runnnig the 2024 R1 student, here are the results showing the static pressure, and the mesh deformation due to the FSI. The air hits the circular solid after coming out of the nozzle and deformes the structure slightly. The mesh plot overlaid with the static pressure shows that it is deformed where the static pressure is. Also attached is a plot of the total pressure (static + dynamic) on the system coupling surface (the circular structure) where the data is transfered, this plot shows that the dynamic pressure on the surface is much greater than the static alone and would deform the solid much more than the static alone…. However, I may be misunderstanding how ANSYS shows the contour plots. Dynamic pressure is perpendicular to the direction of flow so I am not entirely sure if it needs to be accounted for, but the fact that the dynamic pressure contour is showing on the system coupling surface makes me think that it should be accounted for… Any insights on this? 

 

 

 

[Rahul]

Please refer user guide to know about force vector sent from wall boundary in Fluent to System Coupling (refer section 42.4.1): 42.4. Variables Available for System Coupling (ansys.com) and 26.2.1. Computing Forces, Moments, and the Center of Pressure (ansys.com)