# Using fvOptions with interFoam in a rotating framework

 Register Blogs Members List Search Today's Posts Mark Forums Read

 April 16, 2013, 13:01 Using fvOptions with interFoam in a rotating framework #1 New Member   William Case Join Date: Sep 2011 Posts: 6 Rep Power: 6 Dear FOAMers: I am having difficulties applying the fvOptions file (new to OpenFOAM 2.2) to do interFoam calculations in a rotating framework. To get a better understanding, I created a minimum working example (MWE), where I defined a graduated cylinder (100 mm tall x 20 mm radius) using axisymmetry with the centerline following the y-axis. The cylinder is filled 50 mm with water and open to atmosphere on top as shown in the first image (plot of alpha1 variable). I then rotate the cylinder about the axis of symmetry and would expect the water level to rise on the side, but lower in the middle. However, I seem to get no response. In the second image, I should see a rise in pressure at the right side wall. Also attached is the case directory. alpha1.gifpressure.gifcylinder.tar.gz Questions: Q1. Am I defining the cellzones correctly in blockMeshDict (first in blocks statement and 2nd in boundary statement)? Example: Code: ```blocks ( hex ( 0 2 4 1 0 3 5 1) rotor ( 10 50 1) simpleGrading (1 1 1) ); boundary ( wall { type wall rotor; faces ( ( 0 2 3 0 ) // Bottom ( 2 4 5 3 ) // Right ); } atmosphere { type patch rotor; faces ( ( 1 1 5 4 ) // Top ); } ...``` Q2. Am I correctly assuming the fvOptions is the way to add Coriolis and Centrifugal force terms to my momentum equation. Keep in mind that in my actual problem both play a role. Am I correctly describing this? Code: ```MRF1 { type MRFSource; active true; selectionMode cellZone; cellZone rotor; MRFSourceCoeffs { nonRotatingPatches (); origin (0 0 0); axis (0 1 0); omega constant 50; } }``` Q3. Is the variable omega the rotational speed in rad/s? If so, then I have about 5 g's at the right wall, so I should definitely see something. Thank you for your support, Bill

 April 16, 2013, 15:31 #2 Senior Member   Albrecht vBoetticher Join Date: Aug 2010 Location: Zürich, Swizerland Posts: 191 Rep Power: 7 Hi Bill, If you are in a hurry, a work around would be using interDymFoam with rotating the cylinder instead of the framework, might be interesting for comparison to the new fvOptions approach. Of course, computational costs are higher.

 April 16, 2013, 17:29 #3 New Member   William Case Join Date: Sep 2011 Posts: 6 Rep Power: 6 Hello Albrecht It turns out if I let the simulation run longer (endTime = 20 s) I do get a rise in pressure and water begins to climb up the right wall. A look at the velocities shows that they are very slowly catching up to the wall velocity. Additionally the wall velocities at the first time step took on the value (0 0 -1) = r * omega in the -z direction, which tells me the setup and behavior are correct. It happened to respond much slower than I originally guessed. Thank you for the suggestion, though. I may be able to apply what I learned from the testTubeMixer tutorial. Kind regards, Bill

 October 11, 2013, 09:20 #4 New Member   Join Date: Jun 2009 Posts: 19 Rep Power: 8 Looks like you simulated the quite classical Ekman spin-up time problem. A quite good description can be found on this link. http://go.owu.edu/~physics/StudentRe...asto/home.html BR Olle

 Tags fvoptions, mrfinterfoam, rotating cylinder

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post DanM OpenFOAM Running, Solving & CFD 11 January 5, 2013 07:21 Naith FloEFD, FloWorks & FloTHERM 22 November 5, 2012 09:53 Krishna Sandeep OpenFOAM 0 July 3, 2012 04:10 TWaung CFX 4 May 1, 2012 03:14 rystokes CFX 0 January 12, 2010 07:14

All times are GMT -4. The time now is 07:44.