[alvinthum]

Good day, everyone. I am alvin, currently i working on using DPM method to inject calcium carbonate particle from the inlet along the tube with water-liquid fluid (both also using 1.5m/s). My purpose is need to identify the size of particle(2μm,5μm,10μm,20μm,100μm)will affect the number of incomplete particles. The incomplete particle means the particle going to settle down at bottom of the pipe and turbulent dispersion of continuous phase has negligible effect on those particles. Below there is the result based on the paper however when i run the simulation with the method stated by the author, i am not able to obtain similar result. But the result i obtained is zero incomplete particle and all the particle escape from outlet.

Therefore, i wanna know will it be the mesh problem for inlet. Here got two pic, one is the picture for the paper another one is my meshing. I am using sweep mesh by inflating the boundaries.

Or could it be the under relaxation factor since the author had mention using lower under relaxation factor but the author didnt stated the exact value for those factor.

Appreciate to everyone who read the message and hope can get some help from all of you.

May you all be well and happy, alvin.

Result.png

mesh from thesis.png

mesh from alvin.jpg

[Kummi]

Hello Thum,
I am not an expert in this topic but I think you should increase Max. Number of steps under Tracking parameters, in order to track as much as particles you can..And so you can avoid particles escaping from outlet..
I guess there is no problem in mesh.

Good luck :-)

[alvinthum]

Good day Kummi and Appreciate for your help.

In the thesis paper i refer had mentioned that the Max. Number of steps is set in default means 500 only. I just curious about how the boundary condition of the wall will affect the calculation of ansys cause i set the wall in reflect with 0 tangent and 0 polynomial.

May you be well and happy, alvin

[Kummi]

Hello Thum,
Default number of steps is 500, however you can increase it. DPM wall boundary conditions will affect the solution in general. So choose appropriate boundary condition at the wall.

https://www.sharcnet.ca/Software/Flu...ug/node852.htm

Best regards

[alvinthum]

Originally Posted by Kummi

Hello Thum,
Default number of steps is 500, however you can increase it. DPM wall boundary conditions will affect the solution in general. So choose appropriate boundary condition at the wall.

https://www.sharcnet.ca/Software/Flu...ug/node852.htm

Best regards

Noted and thanks you, Kummi. I will work with it.

I have another curious, normally the size of particle will influence the Ansys to track it. For example, 100μm is more difficult than 2μm when ansys want to track it. This is because when i do the simulation with 2μm always show higher number incomplete particles compare to 100μm. But the thesis i refer is mention that 100μm will have higher incomplete particles.(Can refer to my first post).

May you be well and happy, alvin.