Rotating Frame

jordibartrons · September 16, 2011, 15:35

Hi,

Heartly welcome to all fluent users.

i am facing a problem in giving Boundary Condition.

please help me to solve this.

problem is i am having a blade in a cylinder.

i want to simulate the condition while blade rotates.

how to carry out this problem.

m2montazari · September 18, 2011, 16:21

hi jordi and welcome,
to model a rotating blade, you have some options:rotating-reference-frame, sliding-mesh, dynamic-mesh,...
if you have a blade in free stream and there is nothing very close to blade(such as vains and contra-rotatind blade) the simplest model is rotating-reference-frame. the settings is explained in fluent tutorial and you can read it but as an abstract one: first make a grid around the blade in two zones. one zone is a cylinder around the blade and another is all other parts of domain except that cylinder. faces between these two zones must be interior. then after reading mesh in fluent, go to define-boundary condition and set the fluid zone of the cylinder. there you can choose the movement of zone:stationary,moving-reference or moveing mesh. choose second one and then set all walls to ensure correct velocity for each of them(for example the blade wall must be changed to moving wall and a zero RELATIVE veloctiy to adjacent cell zone). hope it helps
yours,
mohammad

jordibartrons · September 19, 2011, 12:38

Thank you very much. I'm trying to do that, but how can I make two grids in two different domains?

m2montazari · September 23, 2011, 03:56

hi,
sorry for lateness. simply make a cylinder-shaped volume around the blade and another volume(or volumes) around that volume. these volumes should have a face(or faces) in common. attention to prevent face duplicatins. both volumes should use the common face. then simply generate grid in each volume and in boundary conditions specify the common face as interior and each of two volumes(or set of volumes) as a fluid zone.
yours,
mohammad

September 16, 2011, 15:35	Rotating Frame	#1
jordibartrons New Member Jordi Bartrons Join Date: Sep 2011 Posts: 8 Rep Power: 15	Hi, Heartly welcome to all fluent users. i am facing a problem in giving Boundary Condition. please help me to solve this. problem is i am having a blade in a cylinder. i want to simulate the condition while blade rotates. how to carry out this problem.

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September 18, 2011, 16:21		#2
m2montazari Senior Member Mohammad Join Date: Feb 2010 Location: Shiraz, Iran Posts: 108 Rep Power: 16	hi jordi and welcome, to model a rotating blade, you have some options:rotating-reference-frame, sliding-mesh, dynamic-mesh,... if you have a blade in free stream and there is nothing very close to blade(such as vains and contra-rotatind blade) the simplest model is rotating-reference-frame. the settings is explained in fluent tutorial and you can read it but as an abstract one: first make a grid around the blade in two zones. one zone is a cylinder around the blade and another is all other parts of domain except that cylinder. faces between these two zones must be interior. then after reading mesh in fluent, go to define-boundary condition and set the fluid zone of the cylinder. there you can choose the movement of zone:stationary,moving-reference or moveing mesh. choose second one and then set all walls to ensure correct velocity for each of them(for example the blade wall must be changed to moving wall and a zero RELATIVE veloctiy to adjacent cell zone). hope it helps yours, mohammad

September 19, 2011, 12:38		#3
jordibartrons New Member Jordi Bartrons Join Date: Sep 2011 Posts: 8 Rep Power: 15	Thank you very much. I'm trying to do that, but how can I make two grids in two different domains?

September 23, 2011, 03:56		#4
m2montazari Senior Member Mohammad Join Date: Feb 2010 Location: Shiraz, Iran Posts: 108 Rep Power: 16	hi, sorry for lateness. simply make a cylinder-shaped volume around the blade and another volume(or volumes) around that volume. these volumes should have a face(or faces) in common. attention to prevent face duplicatins. both volumes should use the common face. then simply generate grid in each volume and in boundary conditions specify the common face as interior and each of two volumes(or set of volumes) as a fluid zone. yours, mohammad