# Inlet velocity profile question

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 September 20, 2019, 04:46 Inlet velocity profile question #1 New Member   demirel suleyman Join Date: Apr 2017 Location: Turkey Posts: 28 Rep Power: 7 Hello all, I have a case where I have to use a velocity profile at inlet which I have from another solver and a different mesh. I'm using a velocity inlet, velocity specification-components with a xyz table. The case is working well, I have good convergence, not any setup problem. My only concern is the velocity magnitude I get. I'm not sure if the values are correctly interpolated from the table to my simulation. I did a calculation to find out the max velocity magnitude from these components I have and the maximum I got it was 10 m/s or something like this and the the max velocity magnitude I get from the solution is around 60 m/s. Do you think is correct? My idea is that not having the same grid position as in the simulation from where I got the velocity profile, star is applying more than one velocity component for example j on the same cell centroid and this could result in this 60 m/s vel magnitude. Any opinion or idea is more than welcome! Thank you, Demirel

 October 4, 2019, 22:38 #2 Senior Member   Ping Join Date: Mar 2009 Posts: 556 Rep Power: 19 not sure where you are saying the 60m/s is occurring in your domain so i suggest you use a threshold to find the high velocity cells - eg about 30m/s. i would also be creating a vector scene containing only the inlet boundary part and then add one or more section planes to the scene just downstream of the inlet and parallel to the inlet to see how your flow develops and whether it looks logical

 October 7, 2019, 08:27 #3 New Member   demirel suleyman Join Date: Apr 2017 Location: Turkey Posts: 28 Rep Power: 7 Hello ping, Thank you for your answer! Sorry for my late edit but I was off the grid in the past few weeks. I did vector planes parallel to the inlet before and everything seem to behave normal. Regarding the Threshold, more than half of the cells in the duct have values higher than 30 m/s but that's ok I created a scalar scene with a plane section on the exact coordinates of the velocity profile BC and the max velocity magnitude is 37 m/s this is why I am concerned, because from my calculations the max velo magnitude on the same plane around 10-11 m/s. I am still confused about this... Mirel

 October 8, 2019, 02:43 #4 Senior Member   Ping Join Date: Mar 2009 Posts: 556 Rep Power: 19 you dont need a section plane 'at' the boundary but instead place the actual boundary part into the scene displayer to confirm what is actually happening on the boundary do this in a vector displayer since this is more useful than a scalar and will show you exactly the magnitude and directions of the applied inlet table you could put the part into a scalar displayer too but this is less useful if these look ok then take a closer look at the threshold just downstream of the inlet and with it set to maybe values greater than 10m/s have you got a recirculation zone near the inlet and if so move your inlet further away using for example a cell extrusion

 October 8, 2019, 04:42 #5 New Member   demirel suleyman Join Date: Apr 2017 Location: Turkey Posts: 28 Rep Power: 7 Hello ping, Thanks for your answer! I will check this stuff. I think I know what I did wrong. I'll get back later. Later edit: Solved! I had to use for my case an extended fluid domain and the velocity profile I got from another project was plotted at a certain xyz position downstream and I was applying the velocity profile somewhere upstream. I moved the new inlet at the same coordinates as the velocity profile and it works. Thank you ping for helping me with this stuff. Mirel Last edited by dmirel; October 8, 2019 at 06:34.