Dear all,
The device I want to simulate looks like this:
In order to realize device simulation, I set the following parameters:
.However, when I conducted data post-processing, I found that the set inlet velocity did not match the actual calculated velocity, as shown in the figure below:
. This is my case.
730.mfx (14.9 KB) . I would like to know whether there is a problem with my settings or whether this is a bug in mfix. If it is a problem set by me, how should I implement the device I simulated?
Hi, it seems that you would like to set a mass inlet with a certain velocity. I guess if you have provided the mass inflow, the velocity you set here is just a reference and will not be considered in your simulation.
You can reduce the inlet area to increase your velocity if you are not going to change the gas volume fraction.
You do not get a specified velocity boundary when you use a mass inflow defined by an STL surface. The MFIX solver internally converts these types of “boundary conditions” to point sources. This is why the GUI only allows you to specify the mass flow rate, just like a point source. You can provide an optional velocity to create a momentum source, however, this value is not imposed like a specified velocity boundary condition.
That said, your mesh is far too coarse for both fluid and PIC calculations. Ideally, you should have at least three full (uncut) cells across the flow width. Most of your flow domain contains no full cells.
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@CFD_Infant and @jmusser Thank you for your answers. I want to know whether the certain inlet velocity can be implemented in this case (such as inlet velocity=10 m/s) ?
Mass inflows can be placed on the domain extents, or on walls constructed using “block regions.” I modified your case (18.5 KB) as an example.
@jmusser I tried this case, and it worked. The idea of this case is very novel. Thank you very much!
