Learning Forum

[niels_normann]

Hallo. I am simulating an heat exchanger where 3 domains exists water (liquid (cold)) flue gas (hot) and solid wall. The domain are disconnected, meaning they are not in contact with each other, i want the heat transfer between the domains. However, for some reason Ansys cfx finds flue gas in my water domain:

[Rob]

As the domains are separate you don't need a multiphase model. Instead you define each fluid region with the material. n

[niels_normann]

Yes, but that is not possible in CFX pre, as i i already stated. If choose water in water domian and then flue in the fluegas domain, then it automatically change the water domian to flue gas. n

[Amine Ben Hadj Ali]

Why are you using multiphase model? This is not a multiphase case (if we now neglect water boiling). Every domain will have its fluid. n

[Surya Deb]

Hello, nIf I understand the issue correctly, thennPlease go to Edit-->Options-->General-->Beta Options-->Physics Beta Features and uncheck Constant Domain Physics. nThis should enable you to have different fluids in different domains. nAlso as Rob and Amine mentioned, you don't need a multiphase model for this.nRegards,nSuryan

[niels_normann]

Thanks for all the replies. I really dont want to use the beta option, as i it is a beta feature. I tried Fluent instead, which made it possible, without any beta feature. n

[Rob]

It's a beta because it was never promoted to full feature for reasons we don't know. I've used it a few times without issue (other than my usual problems using CFX as I don't really know how to). n

[Amine Ben Hadj Ali]

Is not a beta feature at all: that is a standard feature to have different domains using different physics / fluids.n