# Laminar flow simulation in rotating domain

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 November 12, 2011, 02:55 Laminar flow simulation in rotating domain #1 Member   Rahul Vaibhav Join Date: Nov 2009 Location: India Posts: 33 Rep Power: 16 Hi everyone I am doing simulation of rotating cylinder in air at low rpm . there is a heat source inside the cylinder and i want to dissipate heat. For this simulation i am considering a rotating fluid domain around the cylinder of some thickness, can anyone suggest me what should be the thickness of the rotating domain and how many inflation layers i should consider inside it. rv

 November 13, 2011, 17:02 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,729 Rep Power: 143 If in doubt simulate a range of values and do a sensitivity analysis on it. That way you can be sure you are capturing what is important in your application rather than the opinion of somebody on a forum who does not really know what you are modelling.

 June 1, 2014, 06:49 #3 Member   SHEIKH NASIRUDDIN Join Date: Aug 2013 Location: DELHI Posts: 52 Rep Power: 12 Rahul, Glenn Horrocks is correct. Apart from that number of inflation layers will depend on minimum size and max. size of mesh in your domain and growth factor.If min. size is 0.2mm, max size is 2mm and growth factor is 1.2, then 0.2*1.2^(m-1)=2: where m-1=>number of layers required. Nasiruddin

 July 8, 2014, 03:29 #4 Member   SHEIKH NASIRUDDIN Join Date: Aug 2013 Location: DELHI Posts: 52 Rep Power: 12 Hi Rahul, I'm also doing the similar kind of work but not getting expected result. Can you share the boundary condition you have set i.e cell zone condition, vel. inlet, outlet and wall? Thanks in advance.

 July 8, 2014, 10:46 #5 Super Moderator     Alex Join Date: Jun 2012 Location: Germany Posts: 3,400 Rep Power: 47 If the physical setup is a rotating heated cylinder (I wonder what the other boundary conditions are), then I doubt that the correct computational setup is a rotating domain. A rotating boundary condition on the cylinder wall sounds better to me.

 July 8, 2014, 12:05 #6 Member   SHEIKH NASIRUDDIN Join Date: Aug 2013 Location: DELHI Posts: 52 Rep Power: 12 Dear Flotus1, I'm working in Fluent (Ansys-14.5). Can you please tell how to set rotating boundary in Fluent.My domain cylinder along with water flow inside rotates and treated as rotating solid cylinder. Thanks in advance.

July 9, 2014, 03:14
#7
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Alex
Join Date: Jun 2012
Location: Germany
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Quote:
 Originally Posted by flotus1 (I wonder what the other boundary conditions are)
To be more precise, I wonder what ecactly you are trying to model, which results you expect and how exactly the solutions you got so far differ from your expectations. Be descriptive...

 July 9, 2014, 06:19 #8 Member   SHEIKH NASIRUDDIN Join Date: Aug 2013 Location: DELHI Posts: 52 Rep Power: 12 Dear Flotus1, I want to do LES modelling of rotating turbulent pipe flow.Main features to calculate are RMS vel.(x,y&z), Mean vel.(x,y&z),Dissipation rate ,turb. kinetic energy decay and to get energy spectrum to study energy transfer mechanism. To compare these parameters between rotating pipe and stationary pie flow.