Learning Forum

[Joscha Hoppe]

[Saurabh R Patil]

Hi,

I suggest you to check ansys customization manual: A.5. Variables (ansys.com)

Hope this helps you. Let me know if you have any question.

Thank you.

[Rob]

You may want to review C syntax, I don't think 10^(-4) will work. 

Is the viscosity change linked to the solution time, or time since the fluid exceeded a certain temperature? What happens if it cools down again? 

[Joscha Hoppe]

Thank you very much for the answers!
Rob you were right, but the viscosity change i got was wrong since the whole viscosity changed with time and that was not what i wanted.
The viscosity is supposed to change since the fluid exceed a certain temperature. It is supposed to be a simulation of a polymerization process, where the viscosity increases with time. Therefore the after cooling down the viscosity doesnt change. 
I read that i might need a UDS for it, but i would like to know if there is a more simple way.
Greetings

[Rob]

It's complicated, and to an extent beyond where I can help given the nature of the Forum. 

You can use a scalar to track what material has hit the critical temperature, and you can use an additional scalar to track the age of the first one. 

Back into "common knowledge" where I can comment. If a part of your system starts to polymerise does it trigger the whole lot to, or is the initiation temperature still important. The wonders of an old A-level chemistry education. 

[Joscha Hoppe]

Okay, thank you. The initiation temperature is still important. I am simulating a moving porous medium where the polymer is moving through a die, there it becomes heated and then the polymerization reaction starts and the viscosity rises. at the same time the fluid is still moving through the die.

[Rob]

That may become difficult to converge as you start pushing very viscous material through parts of the domain.