Multiphase simulation failing to model sphere-filled composite DEM particle motion

SiemenDiemon · October 10, 2020, 07:25

Hi everyone,

I'm running a Lagrangian Multiphase DEM simulation of a single solid phase mixed in water. My solid phase is a sphere-filled composite particle in the shape of a spheroid:

DEM_particle.PNG

I created an injector for my solid phase at the middle inlet of my geometry (shown in the bottom image) so that the phase is moving in the positive z-direction. When I run the simulation, it seems that the individual spheres in my sphere-filled composite particle model are dispersed in the XY-plane like so (I've counted up the spheres and they always match the number of spheres I used for the composite particle, no matter what I set that number to).

Has anyone seen anything like this before?

simulation.jpg

Cheers

ping · October 13, 2020, 10:21

it looks like your particles are not even getting into your flow domain, as you say they should be heading in the +ve z direction so something bad is happening.

i would back track and inject some simple singles spheres and get that sorted before tracking down the "breakup" issue which is not possible with composite particles anyway.

SiemenDiemon · October 13, 2020, 21:00

Quote:

Originally Posted by ping

it looks like your particles are not even getting into your flow domain, as you say they should be heading in the +ve z direction so something bad is happening.

i would back track and inject some simple singles spheres and get that sorted before tracking down the "breakup" issue which is not possible with composite particles anyway.

Good suggestion, sadly didn't improve anything. One sphere works fine but as soon as I ass more they spread out in the XY plane. I tried setting the injector input by defining a presentation grid with center inside of the flow region further upstream, rather than injecting the particles from one of the faces, but still have the same problem.

SiemenDiemon · December 1, 2020, 18:38

[UPDATE: FIXED]

For anyone interested this issue is actually addressed in the Siemens support center. The solution is to go to your Scalar Scene properties and, under, "Expert", go to "Point Scale Mode" and set to "Particle Model". This fixed it for me.

October 10, 2020, 07:25	Multiphase simulation failing to model sphere-filled composite DEM particle motion	#1
SiemenDiemon New Member Join Date: Sep 2020 Posts: 18 Rep Power: 6	Hi everyone, I'm running a Lagrangian Multiphase DEM simulation of a single solid phase mixed in water. My solid phase is a sphere-filled composite particle in the shape of a spheroid: DEM_particle.PNG I created an injector for my solid phase at the middle inlet of my geometry (shown in the bottom image) so that the phase is moving in the positive z-direction. When I run the simulation, it seems that the individual spheres in my sphere-filled composite particle model are dispersed in the XY-plane like so (I've counted up the spheres and they always match the number of spheres I used for the composite particle, no matter what I set that number to). Has anyone seen anything like this before? simulation.jpg Cheers

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October 13, 2020, 10:21		#2
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	it looks like your particles are not even getting into your flow domain, as you say they should be heading in the +ve z direction so something bad is happening. i would back track and inject some simple singles spheres and get that sorted before tracking down the "breakup" issue which is not possible with composite particles anyway.

December 1, 2020, 18:38		#4
SiemenDiemon New Member Join Date: Sep 2020 Posts: 18 Rep Power: 6	[UPDATE: FIXED] For anyone interested this issue is actually addressed in the Siemens support center. The solution is to go to your Scalar Scene properties and, under, "Expert", go to "Point Scale Mode" and set to "Particle Model". This fixed it for me.