Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
PDE system and deformed geometry
Posted 17.12.2015, 11:39 GMT-5 Geometry, Mesh Version 5.0 1 Reply
Please login with a confirmed email address before reporting spam
Hello,
I have a very simple geometry: segment with a point in the middle. I pretend to simulate the diffusion process of three components by introducing the PDEs in a math interface. The PDE system solves the concentrations of two of the components (the third one must satisfy xA+xB+xC=1). The diffusion process also modifies the geometry. To compute that, I add a deformed geometry interface. I have two main questions:
- I define 0 flux in the edges. I define constant concentration of one of the components in one of the edge points (boundary). The Dirichlet boundary condition node I use to do that, allows me to define the condition for one of the variables or both variables. If I choose only one, the other one should satisfy 0 flux, but such node appears as overriden. Why the 0 flux cannot be defined independent to each variable too?
- Then, in that node I have an external flux for the variable that I want to keep constant. Such flux is used to define the displacement of the node. I define a velocity in the node. But then, I cannot define 0 displacement (fixed) in the middle point! However I can fix the point in the other edge. Why I cannot fix the middle point when one of the edges is moving? (both semi-segments are defined as free deformation)
Thank you
--
M. Sc. Oscar Banos
TU Dresden (Germany)
I have a very simple geometry: segment with a point in the middle. I pretend to simulate the diffusion process of three components by introducing the PDEs in a math interface. The PDE system solves the concentrations of two of the components (the third one must satisfy xA+xB+xC=1). The diffusion process also modifies the geometry. To compute that, I add a deformed geometry interface. I have two main questions:
- I define 0 flux in the edges. I define constant concentration of one of the components in one of the edge points (boundary). The Dirichlet boundary condition node I use to do that, allows me to define the condition for one of the variables or both variables. If I choose only one, the other one should satisfy 0 flux, but such node appears as overriden. Why the 0 flux cannot be defined independent to each variable too?
- Then, in that node I have an external flux for the variable that I want to keep constant. Such flux is used to define the displacement of the node. I define a velocity in the node. But then, I cannot define 0 displacement (fixed) in the middle point! However I can fix the point in the other edge. Why I cannot fix the middle point when one of the edges is moving? (both semi-segments are defined as free deformation)
Thank you
--
M. Sc. Oscar Banos
TU Dresden (Germany)
1 Reply Last Post 18.12.2015, 10:21 GMT-5
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
For those who may be interested. I found the solution for the second question. If I add another node, appart from the default node for the "Prescribed mesh displacement", I can define the system as I want. That is, I can select the middle point and impose a zero displacement.
--
M. Sc. Oscar Banos
TU Dresden (Germany)
--
M. Sc. Oscar Banos
TU Dresden (Germany)