The difference between the current fixed and mobile blade row in CFX
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Dear users CFX
tell me, what's the difference between the calculations turbo machines with rotating and stationary blade row but with the feed stream at an angle? Will the results be different? Attachment 44625 https://www.youtube.com/watch?v=PCM2_UKG6Mw |
If the blades are just translating then there is no difference. If the blades are rotating then rotational effects occur - centripetal and coriolis accelerations. These accelerations will make cases 1 and 2 different.
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Your case 1 = Rotating frame of reference rotor blade row, but case 2 = Stationary frame of reference stator blade row.
Case 2 will have an inlet flow angle based on the inlet velocity triangle from U and C1, but will be a non-rotating cascade flow without the additional effects of Coriolis terms. |
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Link Attachment 44823 Attachment 44824 Thanks for help! |
Your question is unclear to me, but
I guess your model is R1 of rotating frame, but the inlet flow is axial leading to a flow separation. If the flow vector is on the relative streamline, it means your inlet relative velocity (W1) is purely axial. Two possible reasons : (1) the blade velocity (U1 = r1*omega) is zero (2) the inlet absolute velocity vector has a big angle, so that W1 becomes axial. I do not understand what you meant by "I've set centrifugal velocity (x) to 0". I guess it could be (1). |
I think your images do not illustrate your setup completely.
Please add the image for the Domain panel the inlet is attached to, and the image of the Basic Settings tab on the boundary as well. So far, the only we can tell is that you specified the inlet velocity in Cartesian Components and the flow is subsonic. It is impossible to tell w/o the other two images, if you specify this velocity in the rotating frame, or the stationary frame. Hope the above helps, |
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this screen my cordinate, from BC file. i think than U in is velocity to X cordinate. At first I solve with rotating domaine, in post CFX I get BC file, than set stationary in setup of domaine. Install BC profile without centrifugal velocity U (if i think right). |
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Attachment 44846 Attachment 44847 I can not instal velocity in Cartesian Components because I want to have different angle vectors of velosity on radius of blade |
Sorry, still why you are doing this is unclear to me due to imperfect communication.
Your domain turned out to be stationary under the name of "R1" though. From your posted inlet velocity profile, the inlet flow is almost axial because u1=0 and v1 << w1 (= z direction velocity = axial velocity). You solved a staggered stator vane row with an axial inlet flow, resulting in of course the large stall. I think you look confused between (u,v,w) absolute 3D velocity components and (U,V or C,W) turbomachinery velocity triangle notations. They are totally different. |
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