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sile March 5, 2003 12:44

Help! Coupled Vs Implicit - Total temperature
Hey All! I am modelling internal compressible fluid flow. There should be no heat transfer in my model and I was expecting total temp to be a const, this is the case with the segregated solver but with the coupled one there is a large variation, I would be really grateful if anyone could shed some light on this for me! thanks in advance

Chris March 10, 2003 08:10

Re: Help! Coupled Vs Implicit - Total temperature
I have experienced a similar problem to yours. Someone told me that it could just computational error...what percentage variation is yours? (mine was about 10% of my total temperature)

If anyone else could offer advice, that'll be much appreciated

sile March 10, 2003 08:42

Re: Help! Coupled Vs Implicit - Total temperature
The percentage variation in mine is about 4% of the total temperature. I've been told similar things about it being a possible computational effect but I'm noticing some pretty strange behaviour so I'd like to get to the bottom of it!

Jonas Larsson March 10, 2003 16:58

Re: Help! Coupled Vs Implicit - Total temperature
Interesting observation. It is not that often that you take the time to compare results obtained with different solvers. I have checked it a few times on subsonic turbomachinery flows and have never seen big errors on well-converged solutions. I also remember checking the same thing for air-intake simulations and results with different solver were also very similar there. These were all subsonic flows. If you have supersonic or transonic flows with shocks expect the segregated solver to not be very accuarate.

If you find the cause if this please share it with us.

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