Hej,
I am trying to simulate the pressure waves propagating in some mm thick cavitiy. I defined Navier-Stokes solver on a body and a Pressure wave on a a boundary. The rest I defined a non-slip condition.
Pressure profile is shown on the .SIF file. It has a 25 Hz frequency.
To achieve stationary I already tried:
- Gradp Gradient = Logical True
- Refined the mesh.
- Bubbles = Logical True
- Decrease time step size.
- Decrease average and amplitude of the pressure wave deinfed on the boundary.
- Decrease relaxation factor.
There is no way I can overcome the transient, it has always crashed first. Nothing seems to work.
Thanks in advance,
/Xavi
Navier-Stokes: Pressure profile BC
Navier-Stokes: Pressure profile BC
- Attachments
-
- test.tar.gz
- sif_and_mesh
- (877.01 KiB) Downloaded 228 times
Re: Navier-Stokes: Pressure profile BC
Hej!
Something funny...
If a null velocity,
Velocity 1 = 0
Velocity 2 = 0
is set at the same boundary where the pressure profile is defined (Boundary 1);
the simulation perfectly converges.
I am not that much into N-S. However, since the frequency of the pressure profile is 25 Hz shouldn't this affect that much the results right?
I am thinking on estimating somehow the velcoity profile at the entrance so I do not apply the restrictive null velocity there and still have convergent results.
/Xavi
I attach a snap to show the results![Wink ;)](./images/smilies/icon_e_wink.gif)
Something funny...
If a null velocity,
Velocity 1 = 0
Velocity 2 = 0
is set at the same boundary where the pressure profile is defined (Boundary 1);
the simulation perfectly converges.
I am not that much into N-S. However, since the frequency of the pressure profile is 25 Hz shouldn't this affect that much the results right?
I am thinking on estimating somehow the velcoity profile at the entrance so I do not apply the restrictive null velocity there and still have convergent results.
/Xavi
I attach a snap to show the results
![Wink ;)](./images/smilies/icon_e_wink.gif)
- Attachments
-
- Namnlös.png
- Solution
- (346.56 KiB) Not downloaded yet
Particle Dynamics (Re: Navier-Stokes: Pressure profile BC)
PARTICLE DYNAMICS
Hej,
from the case explained above I tried to add some particles to check if there is actually a movement of gas/oil/dust... when having a 25Hz pressure wave on a boundary.
I have been able to run the Model 29: Particle Dynamic however I cannot understand how the particles are intially placed. I am using the "random box" however the particles are only located on one part of my model. The particles migrates till other parts of the model with time however I am not able to place them where I want them to be.
Could someone experienced on the Particle Dynamic Solver explain me how the "Initial Position" command work? I attach a snap showing the problem I have (paticles just on one side).
Hej,
from the case explained above I tried to add some particles to check if there is actually a movement of gas/oil/dust... when having a 25Hz pressure wave on a boundary.
I have been able to run the Model 29: Particle Dynamic however I cannot understand how the particles are intially placed. I am using the "random box" however the particles are only located on one part of my model. The particles migrates till other parts of the model with time however I am not able to place them where I want them to be.
Could someone experienced on the Particle Dynamic Solver explain me how the "Initial Position" command work? I attach a snap showing the problem I have (paticles just on one side).
- Attachments
-
- Namnlös.png
- particles_just_on_one_side
- (119.45 KiB) Not downloaded yet