pump us turbine domain interface

akelile · March 20, 2019, 10:14

hi their?

i'm working on pump as turbine, and I'm having trouble with pitch change. I am using frozen rotor for the frame change and when i use pitch angle automatic or none. it gives me a message that the option is invalid.

Is there any body with idea or a solution?

it is very much appreciated

AtoHM · March 25, 2019, 02:25

It is hard to follow what you are doing from your explanation.
Pitch change is used to describe a circumferential difference between two adjacent domains (stationary/rotating). You can find images and an explanation in the cfx user guide.

If you change it to "None", CFX usually gives a warning message, not an error. If its just a warning and you really model 360° of the interface on both sides, you can ignore it.

urosgrivc · March 25, 2019, 03:58

why are you opening so many new posts
one is here below and I have seen another one somewhere
pitch angle ratio

Ok The answer to that one is , if this is the same problem you are talking about, is that you actually need 360°of the rotor so you can connect it to 360° of the stator and select pitch change to none.

I think slide 9 and 12 are most relevant for you but check out all of the slides.
https://slideplayer.com/slide/9398929/

look at stage interface
https://www.sharcnet.ca/Software/Ans.../CACDIGEH.html
This should work if you want to do it like you are triing to (only a part of rotor used in the sim)

But I am not completly sure if this is apropriate, I would use a full 360 model

March 20, 2019, 10:14	pump us turbine domain interface	#1
akelile New Member addis abeba Join Date: Aug 2018 Posts: 2 Rep Power: 0	hi their? i'm working on pump as turbine, and I'm having trouble with pitch change. I am using frozen rotor for the frame change and when i use pitch angle automatic or none. it gives me a message that the option is invalid. Is there any body with idea or a solution? it is very much appreciated

March 25, 2019, 03:58		#3
urosgrivc Senior Member urosgrivc Join Date: Dec 2015 Location: Slovenija Posts: 365 Rep Power: 11	why are you opening so many new posts one is here below and I have seen another one somewhere pitch angle ratio Ok The answer to that one is , if this is the same problem you are talking about, is that you actually need 360°of the rotor so you can connect it to 360° of the stator and select pitch change to none. I think slide 9 and 12 are most relevant for you but check out all of the slides. https://slideplayer.com/slide/9398929/ look at stage interface https://www.sharcnet.ca/Software/Ans.../CACDIGEH.html This should work if you want to do it like you are triing to (only a part of rotor used in the sim) But I am not completly sure if this is apropriate, I would use a full 360 model Last edited by urosgrivc; March 25, 2019 at 07:55.

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March 25, 2019, 02:25		#2
AtoHM Senior Member M Join Date: Dec 2017 Posts: 645 Rep Power: 12	It is hard to follow what you are doing from your explanation. Pitch change is used to describe a circumferential difference between two adjacent domains (stationary/rotating). You can find images and an explanation in the cfx user guide. If you change it to "None", CFX usually gives a warning message, not an error. If its just a warning and you really model 360° of the interface on both sides, you can ignore it.