[zdz198728]

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]

Originally Posted by zdz198728

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]

Dear zdz198728,

Could you please send me the tutorial of erosion ?

[Manathan]

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`]

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]

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

[naqiubex]

Originally Posted by `e`

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.

I was thinking to change the erosion rate to mass/time instead of mass/area-time. Therefore, do I have to modify the equation by not dividing it by the face area of the wall?

Am I correct at doing this. Tq.