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-   -   Question about Fluent DPM erosion model (http://www.cfd-online.com/Forums/fluent/98313-question-about-fluent-dpm-erosion-model.html)

zdz198728 March 7, 2012 20:24

Question about Fluent DPM erosion model
 
Hi, Guys,
I am currently working on an erosion problem in the pump. I tried DPM erosion model exactly follow the tutorial, but seems I can't get the mass balance for particle at inlet and outlet. the number of particle insert is larger than the particle escaped. Also, there are some particle shows in "imcomplete". it is like some particles have been lose track.

Also, in the erosion tutorial, they use velocity inlet type. When I change it to mass flow inlet, the case stopped when DPM iteration starts.

Could any one help me out about this question? Thanks.

Messi June 20, 2014 05:58

Quote:

Originally Posted by zdz198728 (Post 348251)
Hi, Guys,
I am currently working on an erosion problem in the pump. I tried DPM erosion model exactly follow the tutorial, but seems I can't get the mass balance for particle at inlet and outlet. the number of particle insert is larger than the particle escaped. Also, there are some particle shows in "imcomplete". it is like some particles have been lose track.

Also, in the erosion tutorial, they use velocity inlet type. When I change it to mass flow inlet, the case stopped when DPM iteration starts.

Could any one help me out about this question? Thanks.

Mass balance of erosion:
injection flow rate= accretion rate+escape rate+imcomplete.

YANNAPOL February 21, 2015 04:51

Dear zdz198728,

Could you please send me the tutorial of erosion ?

Manathan May 4, 2015 10:44

I'm sorry but I have to disagree with your definition (or I missed something) :
the accretion rate is given in kg/m2-s while the injection "mass" flow rate is in kg/s.

Or is it possible to obtain the injection flow rate for each particle so in kg/m2-s ?

`e` May 4, 2015 19:11

Firstly, be careful of units and validate your simulations by comparing results with experiments. If the accretion rate is given as a flux (kg/m^2.s) then it's likely Fluent divides the particle stream mass flow rates (kg/s) by the impacted face area (m^2). You could multiply this flux by the face area to calculate the particle mass deposition rate (kg/s).

I found the accretion/erosion model in Fluent restrictive and have used UDFs at the boundary to monitor deposition.

Manathan May 5, 2015 03:10

completely agree with you, especially for 2D axisymmetric, the area impacted is unclear in the user guide.


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