Learning Forum

[Clément Bouchard]

Hello, 

 

I'm simulating a liquid flow in the airways and I need to see the particle deposit in them. Here are the parameters used

I define my DPM on escaped for the inlet and my 2 outlet and trap on the wall. I try to have a similar result like this but in 3D : 

 

This is my geometry : 

I can't see a similar result as before. Hoping that someone can help me. 

 

Thanks.

 

[Rob]

In the first image I suspect those are particles that are suspended in the liquid but may be caught in low flow regions. The DPM model does have an accretion model, but that returns a mass per area contour plot and not particle positions. 

[Clément Bouchard]

Thanks for yo answer, do you know if it is possible to show me which parameters I have to choose in the discrete phase model to have the result I want in my simulation.

Thanks.

[Rob]

The first image? Have a look at scenes (Particle Trajectories & Mesh). Also look at how you set up the DPM model, is it steady or transient? For the former you'll see a in-to-out trajectory track for the latter a load of dots/spheres of the particle position at the time the image is saved. 

[Clément Bouchard]

When I create an animation (which is what I want to do in the end), I see the path of the particles from the input to my 2 outputs, and otherwise, in a simple simulation without scene or animation, I see the position of the particles in the saved image. But I can't see how they settle on the wall.

[Rob]

Simple tracks in steady, have a look at the Pulse option & Save Pulse Animation. 

For transient have a play. 

[Clément Bouchard]

Thanks, I have this video of my particle on my piece. Here a photo suring the video :

But like i say in my first message I have to see the deposit of the particle on the wall and for the moment I see just their movement. 

Thanks.

[Rob]

The initial image doesn't look like deposition, it looks like particles in slow regions. The DPM model uses a point mass, so you really don't want to try and see a build up. For that you'd be looking at Rocky DEM. 

[Clément Bouchard]

 

 

Ok thanks for you answer, but Rocky DEM it is include in the Ansys License ? Because I haven’t this module in Ansys Workbench.

Thanks

 

 

[Rob]

Possibly not. I'd use DPM and use the surface contour accretion or the UDF example to map parcel deposition mass onto the vessel surface. 

[Clément Bouchard]

Can you explain these two methods to me in detail, I'm not sure how to do them. Thank you

[Rob]

Have a look at the accretion models in the User's Guide. You need to activate the model in the DPM panel, and that will return a contour of mass/facet area/second for a steady model or mass/facet area in transient. The UDF works in much the same way but you adjust the effect of impact angle etc on the accretion rates. 

[Clément Bouchard]

I have choose the accretion in physicals models in DPM : 

But the results doesn't change. 

Equally I have try with the UDF but my simulation didn't work. I couldn't run a calculation. I don`t know why. It was good when I have choose accretion in physicals models ?

 

Thanks

 

 

[Rob]

I don't know what you set in the UDF so difficult to comment. Have a look at the accretion plot in contours: the DPM trajectories should remain as before. 

[Clément Bouchard]

 

 

 

For DPM I have use this parameters :

But I don’t really understand what i supposed to see in contours,

 

Thanks

 

 

 

[Rob]

The accretion rate; ie the rate at which particles deposit. 

[Clément Bouchard]

I have a big difference in accretion rate near my entrance and more towards the middle of my geometry. 

So, I can see a deposition with the contours but do you know how it is possible to have animation video with the deposition of particle.

 

Thanks

[Rob]

Probably too few parcels hitting too fine a surface mesh. Contour animations will be covered in the various tutorials.