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My radial inflow turbine

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Old   December 11, 2016, 20:14
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Ahmad Hari
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Hi Brian,

1- the flow direction was based on Turbo comment. Since the axis of rotation is Z, I set x = - 1, y = tan (78.33) and Z= 0. I doubly I have a problem here

2- yes the efficiency was calculated by Rital (Comcept NREC). In Rital, I designed a turbine with volute and rotor ( no stator). So, the enthalpy drop should take place at the rotor.
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Old   December 12, 2016, 08:20
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Why did you use the compressor template in performance?
Post a 3d streamline view.
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Old   December 12, 2016, 09:03
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Hi Turbo,

I'm not using compressor template. I'm using turbine rotor template but I don't know why it appears as a compressor. Attached is the screenshot of the velocity streamlines
Attached Images
File Type: jpg velocity streamlines.jpg (74.6 KB, 26 views)
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Old   December 12, 2016, 09:49
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Before trying any CFD, bear in mind that you need to study the basics of turbomachinery, especially the velocity triangle.

Your geometry setting needs a negative rpm. There will be more to fix other than that. Just study setting aside the CFD job.

This forum is not aiming for providing turbomachinery education, as I know.
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Old   December 12, 2016, 11:08
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That's correct but I would be happy if you mentioned "the more things need to be fixed" though
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Old   December 12, 2016, 18:42
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Based on the picture, rpm needs to be negative. Also, your inlet flow direction needs to be in the same direction as the rotation. Based on the axes you have, I think you need z=0, y=-1 and x = tan(78). I would strongly recommend reviewing this resource if you need a turbomachinery reference: https://www.google.com/url?sa=t&rct=...feI6rXhjuNutww

Turbo is correct. You need to review the basics of turbomachinery so you can troubleshoot your CFD. Chapter 8 of this resource is for radial turbines, but there is a good general review in the first few chapters as well. Best of luck!

Last edited by bparrelli; December 12, 2016 at 19:57.
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Old   December 13, 2016, 11:17
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Dear Brian, Turbo and all,

Thank you for your comments and advices. I'll keep working on that till it is fixed.

Brian,

Using the flow direction you mentioned (z=0, y=-1 and x = tan(78).), I got the following error:

ERROR #002100024 has occurred in subroutine ASS_FLX_BDINIP. |
| Message: |
| The specified flow direction on boundaries must not be tangential |
| to the boundary. However, on the boundary patch |
| |
| R1 Inlet |
| |
| a specified flow direction having an angle of 6.2 degrees |
| was found, which the solver considers as being nearly tangential. |
| Please do one of the following: |
| (1) Check your direction specification on this boundary. |
| (2) Set the 'Flow Direction Linearisation' to 'Velocity Magnitude' |
| in your boundary specification. |
| (3) Modify the solver tolerance by decreasing the expert parameter |
| 'tangential vector tolerance' below its default of 10 degrees.


I will try to follow the comments suggested by CFX

Thanks again all of you
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Old   May 11, 2018, 02:44
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Quote:
Originally Posted by Abo Anas View Post
Continue of the attached photos

Just to let you, I'm using Cartesian coordinates based on comment by Turbo. I have a swirl angle (absolute flow angle) = 78.33 deg

Many thanks in advance
Anas. Hi. Have you solved your issues. I need to do similar simulation and I only have 2 days to work on it. Please, can you reply.
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