# Is it possible to split the simulation into two steps?

 Register Blogs Members List Search Today's Posts Mark Forums Read

 May 16, 2022, 21:40 Is it possible to split the simulation into two steps? #1 New Member   Junyeol Join Date: Mar 2022 Posts: 18 Rep Power: 4 Dear forum users, I want to split the simulation into two steps so that those two steps are connected. If I simply want the value of the pressure gain to change, I can change the input flow rate, but what I want to do is change the boundary condition of the surface according to the steps. (eg, Outlet>>Wall) Is it possible to change the boundary condition according to the stage while the two stages are fluidly connected?. Thank you for your help as always.

May 17, 2022, 02:14
#2
Super Moderator

Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,786
Rep Power: 143
Can you explain what you are trying to do more?

Pressure gain of what?
What change to the boundary condition do you want to do? What do you mean by steps?

Quote:
 Is it possible to change the boundary condition according to the stage while the two stages are fluidly connected?.
What do you mean by "stage"?

Please show a diagram of what you want to do.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

May 17, 2022, 02:31
#3
New Member

Junyeol
Join Date: Mar 2022
Posts: 18
Rep Power: 4
Quote:
 Originally Posted by ghorrocks Can you explain what you are trying to do more? Pressure gain of what? What change to the boundary condition do you want to do? What do you mean by steps? What do you mean by "stage"? Please show a diagram of what you want to do.

My English is not good enough. Sorry.

To state the simulation that I want to do ultimately, I want to cut off the flow of the part where the flow passed during the experiment.

So, I wonder if it is possible to transform the part set as an outlet into a wall at a specific time.
Therefore, in the first case where one wall is an outlet, and in the second case where one wall becomes a wall after proceeding in the first case, I wonder if a divided analysis in this way is possible.

Thank you always.

 May 17, 2022, 02:45 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,786 Rep Power: 143 I do not quite understand what you are trying to do, but it is simple to change a boundary condition type (maybe a wall to an outlet) by stopping the simulation, editing the boundary in CFX-Pre to the new boundary condition type, and then restarting the simulation using the first simulation as an initial condition. This will use the flow from the first boundary condition setup and the initial condition for the second boundary condition. Is this what you want to do? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

May 17, 2022, 02:57
#5
New Member

Junyeol
Join Date: Mar 2022
Posts: 18
Rep Power: 4
Quote:
 Originally Posted by ghorrocks I do not quite understand what you are trying to do, but it is simple to change a boundary condition type (maybe a wall to an outlet) by stopping the simulation, editing the boundary in CFX-Pre to the new boundary condition type, and then restarting the simulation using the first simulation as an initial condition. This will use the flow from the first boundary condition setup and the initial condition for the second boundary condition. Is this what you want to do?
That method seems to fit the simulation I want to do. I'll give it a try. thank you.