On the issue of two-dimensional simulation

MFiX How to
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#1

Hello, researcher. I have two very confusing questions, as follows:

  1. I am currently confused about the concept of two-dimensional simulation, as shown in the following figure. Regardless of the size of the rectangular model, as long as the number of grids in the Z-axis direction is 1, it can be considered a two-dimensional simulation. Is this understanding correct?

  2. Do we need to establish wall boundaries when conducting two-dimensional simulations? I checked the user manual and said: as long as the number of grids in the Z-axis direction is 1, there is no need to establish wall boundaries. If that’s the case, what should I do when I need to set the boundary temperature for 2D simulation?

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#2

Can someone help me? Thank you very much.

#3

Hi. Most of the MFiX team is on holiday break. We will get back to you as soon as possible.

#4

I believe you are correct about question #1 - a simulation with a single cell in the Z-direction is considered 2-dimensional, regardless of the size in the Z axis.

Regarding question #2 - although it is not necessary to set up the Z-boundary walls, I believe that it is still permissible to do so, for example if you need to specify wall temperature, etc.

#5

Hello Charles, I’d like to ask you how the wall thermal conductivity mfix is calculated when the z-boundary wall is not defined.

#6

It would be adiabatic wall by default.

#8

Can you please show us what you mean?