[YANNAPOL]

Dear All,

I am simulating particle deposition at the wall.
My geometry is 3D nozzle, inlet from above and outlet below.
I use DPM model in order to simulate this problem

Model
1) k-epsilon, std wall function
2) main flow velocity(Water Liquid) is 0.1 mm/s
3) nozzle length is 0.5 mm
4) particle velocity = 0
5) No external pressure, gravity and
6) Wall_BC non-slip condition


The problem is the particle does not reach the wall, so UDF does not applicable and particle does not deposit. Theoretically, that is may be true.

I check my UDF by apply unrealistic initial normal velocity for particle.

My question is .....
Actually, one of the way to make particle reach the wall is to change the wall shear condition (Wall Slip Condition), unfortunately the calculation does not converge.
Another way is to define the force between particle and wall(may be written by UDF). but don't know how to do that......

What should I do... are there any ways to make particle reach the wall ?

Please kindly advise


Best Regards,
Yannapol S.

[husywfl]

Originally Posted by YANNAPOL

Dear All,

I am simulating particle deposition at the wall.
My geometry is 3D nozzle, inlet from above and outlet below.
I use DPM model in order to simulate this problem

Model
1) k-epsilon, std wall function
2) main flow velocity(Water Liquid) is 0.1 mm/s
3) nozzle length is 0.5 mm
4) particle velocity = 0
5) No external pressure, gravity and
6) Wall_BC non-slip condition


The problem is the particle does not reach the wall, so UDF does not applicable and particle does not deposit. Theoretically, that is may be true.

I check my UDF by apply unrealistic initial normal velocity for particle.

My question is .....
Actually, one of the way to make particle reach the wall is to change the wall shear condition (Wall Slip Condition), unfortunately the calculation does not converge.
Another way is to define the force between particle and wall(may be written by UDF). but don't know how to do that......

What should I do... are there any ways to make particle reach the wall ?

Please kindly advise


Best Regards,
Yannapol S.

Hi YANNAPOL，

Can you post your UDF? As I'm also doing simulation about particle deposition, I want to simulate the morphology change of the wall after particle deposited, but I don't know how.

For the problem particle does not reach the wall, maybe you can try the "Discrete random walk model" in the injection panel.

Good luck,
Wfl

[YANNAPOL]

Dear husywfl,

I already have tried Discrete Random Walk in injection panel, but it seems to be indifferent.
Actually, I am quite new with this.
Are there any factor I should change to increase chance of particle attach the wall ?
I may miss something, please kindly advise.

Should I use DEM couple with DPM ?

Another question, I activated the stochastic collision. After that, there is no particle injected from the inlet surface. Why ?

Best Regards,
Yannapol S.