I'm kinda new to surface modelling in SW and I'm trying to model a lobetype pressure vessel, which has partitions between lobes. I've been trying to knit the surfaces so I eventually end up with a merged model. So far I've been using the Check feature to see where I have open surfaces, yet when I try to knit & merge the surfaces that are open I keep getting the error "The selected faces and surfaces cannot be knitted into one surface" and I'm kinda lost to what I should do to solve this problem. I can knit the outer surfaces together, but when it comes to knitting the partitions to the outer surfaces I get this problem.
The whole point of doing this modelling is to load my model as an IGES file into Ansys Mechanical and do a FE analysis. If it helps I've attached the file.
Can anyone here please help me with this problem?