Fluent Pre : "Absolute" and "Relative to adjacent cell zone"

kastarkas · September 30, 2016, 03:29

Hello friends,

A simple doubt.

Solver : Fluent

Problem : Steady, MRF, Frozen Rotor, Centrifugal Pump.

Domains : 2 (Rotating and Stationary Domain)

Parts of Rotating domain :impeller blades and a counter rotating (fixed)bottom wall.

Setup :
1. Domain rotation applied.

2. Bottom surface or the fixed counter rotating wall (as we say in CFX) is also set a Rotating wall with its motion specified as "Absolute".

3. Impeller disc with blades set as Rotating Wall with relative motion as "Relative to adjacent cell zone" (adj. cell zone, here is rotating zone).

I have seen in all the tutorials, videos, doing the same, for which they might have their fixed parts, (which are not intended to rotate, but still falling in the rotating domain) as some hub, or some fixed circular support frames, etcc...

Is this right ?

I am pretty sure that nothing is wrong with the selection of my linkage equations, turbulence models, mesh, all the other BC's, initialisation..etc..

I made the solver run .This is what i got .

(a)Continuity residual goes straight line

(b)all the other residuals try to reach a max convergence of 10^-1 or hardly 10^-2.

(c) i tried various combo of BC's @ inlet and outlet, but still this is same and sometimes it goes even above 10^0.

I am running this great in CFX and it converges easily.

Any sort of help is blissful.

Thank you all in advance.

kastarkas · September 30, 2016, 07:49

fluent prob.JPG

i am attaching the image of my solver run in its initial few iterations..

it is either like this or its a straight line..

Thank you.

kastarkas · October 4, 2016, 03:52

Hello can anyone please respond...?

September 30, 2016, 03:29	Fluent Pre : "Absolute" and "Relative to adjacent cell zone"	#1
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	Hello friends, A simple doubt. Solver : Fluent Problem : Steady, MRF, Frozen Rotor, Centrifugal Pump. Domains : 2 (Rotating and Stationary Domain) Parts of Rotating domain :impeller blades and a counter rotating (fixed)bottom wall. Setup : 1. Domain rotation applied. 2. Bottom surface or the fixed counter rotating wall (as we say in CFX) is also set a Rotating wall with its motion specified as "Absolute". 3. Impeller disc with blades set as Rotating Wall with relative motion as "Relative to adjacent cell zone" (adj. cell zone, here is rotating zone). I have seen in all the tutorials, videos, doing the same, for which they might have their fixed parts, (which are not intended to rotate, but still falling in the rotating domain) as some hub, or some fixed circular support frames, etcc... Is this right ? I am pretty sure that nothing is wrong with the selection of my linkage equations, turbulence models, mesh, all the other BC's, initialisation..etc.. I made the solver run .This is what i got . (a)Continuity residual goes straight line (b)all the other residuals try to reach a max convergence of 10^-1 or hardly 10^-2. (c) i tried various combo of BC's @ inlet and outlet, but still this is same and sometimes it goes even above 10^0. I am running this great in CFX and it converges easily. Any sort of help is blissful. Thank you all in advance.

September 30, 2016, 07:49		#2
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	fluent prob.JPG i am attaching the image of my solver run in its initial few iterations.. it is either like this or its a straight line.. Thank you.

October 4, 2016, 03:52		#3
kastarkas Member kastarkas Join Date: Aug 2016 Posts: 45 Rep Power: 9	Hello can anyone please respond...?