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#1 |
Senior Member
Pedro Oliveira
Join Date: Feb 2018
Location: Portugal
Posts: 109
Rep Power: 8 ![]() |
I´m using water with IAWPS table generation values.
I notice that the maximum total pressure I obtain at the CFX-Post is the value I defined as the maximum table pressure value (350 bar). After this I increased this value and I verified again that the total pressure value obtained on the CFX-Post was again the new maximum value I have defined ( 450 bar). What I conclude is that the maximum pressure value I use in my table generation it small compared to the real value and I have increased the value again ( 500 bar). Only that now, my simulation that runned perfectly it crashes right before the beggining of the first coeficient loop of the first iteration. With a value higher that 450 bar, in my case, the simulation crashes, does anybody knows why or how I can solve this problem? |
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#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,816
Rep Power: 144 ![]() ![]() ![]() ![]() |
Advanced material models like IAWPS are often hard to converge. I would recommend you first do a simulation using simple, fixed material properties. This should be easy and converge quickly. The result of that will estimate what the maximum pressure you are going to get it, then you can size you table range correctly and return to IAWPS.
Assuming you still have convergence problems after this, the first things to try are the normal ones for numerical instability: double precision numerics, better mesh quality, smaller time step, better initial condition.
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Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
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#3 |
Senior Member
Pedro Oliveira
Join Date: Feb 2018
Location: Portugal
Posts: 109
Rep Power: 8 ![]() |
I already estimated the maximum pressure as you say and its lower then the maximum I can use to get convergence. I thought that maybe I was missing something about the table generation. I´l try the mesh improvement first.
Thank you for all your help, Best Regards |
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