[annagoco]

Hello, I am trying to simulate a parafin deposition model using CFX. In order to facilitate my job I am trying to apply a bingham behaviour for the viscosity of my fluid with yield stress as a function of temperature. I dont think i can use an expression for the yield stress so now I am thinking about creating an expression for my viscosity. So I have 2 questions:
1) I would like to calculate the sheer stress in my fluid. There is not a variable for that in cfx. There is one for sheer strain rate but the relationship between the two is quite complicated for my flow. its a flow in a annular section with different temperatures in the inner and outter walls. Has here tried something similar?
(2) what kind of numerical issues might appear because of this model?

Anyways, I am having a hard time figuiring out a solution for this. I am a grad student, havent used CFX for a long time, pretty new to it.

Thank in advance,
ANNA

[soto6942]

Originally Posted by annagoco

Hello, I am trying to simulate a parafin deposition model using CFX. In order to facilitate my job I am trying to apply a bingham behaviour for the viscosity of my fluid with yield stress as a function of temperature. I dont think i can use an expression for the yield stress so now I am thinking about creating an expression for my viscosity. So I have 2 questions:
1) I would like to calculate the sheer stress in my fluid. There is not a variable for that in cfx. There is one for sheer strain rate but the relationship between the two is quite complicated for my flow. its a flow in a annular section with different temperatures in the inner and outter walls. Has here tried something similar?
(2) what kind of numerical issues might appear because of this model?

Anyways, I am having a hard time figuiring out a solution for this. I am a grad student, havent used CFX for a long time, pretty new to it.

Thank in advance,
ANNA

hi could you solve your problem i am working in a plastic bingham and i do not know much