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#1 |
Member
Ralph
Join Date: Mar 2009
Posts: 40
Rep Power: 17 ![]() |
Hi,
I want to simulate a pitching airfoil. My question is about the boundary conditions. 1) As there is a non constant velocity of the wall along the airfoil, I canīt use the fixedValue boundary condition. Is the following boundary condition applicable for U? AIRFOIL { type movingWallVelocity; value uniform (0 0 0); } Does it mean, that there is a zero relative velocity forced at the wall? 2) Can I leave the boundary conditions for all other variables as they are in the case with non-moving walls? Ralph |
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#2 |
Member
Ralph
Join Date: Mar 2009
Posts: 40
Rep Power: 17 ![]() |
Hi,
I want to simulate a pitching airfoil. My question is about the boundary conditions. 1) As there is a non constant velocity of the wall along the airfoil, I canīt use the fixedValue boundary condition. Is the following boundary condition applicable for U? AIRFOIL { type movingWallVelocity; value uniform (0 0 0); } Does it mean, that there is a zero relative velocity forced at the wall? 2) Can I leave the boundary conditions for all other variables as they are in the case with non-moving walls? Ralph |
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#3 |
Senior Member
Frank Bos
Join Date: Mar 2009
Location: The Netherlands
Posts: 340
Rep Power: 18 ![]() |
Hi Ralph,
1) You need the movingWallVelocity boundary condition for U on the moving wall. This boundary condition corrects the flux due to mesh motion in such a way that the total flux phi through the moving wall is zero. The way it should be the case, you can check phi in the time dirs. 2) When you are using icoDyMFoam, you only have motionU, U and p. Leave p and the rest of U like in case of nonmoving wall. In motionU define the motion of the wall by applying the oscillationFixedValue BC, or take fixedValue (0 0 0) when the motion of the wall is defined by using a dynamicFvMesh lib. To be safe, take fixedValue (0 0 0) on all outer boundaries, except the symmetry and empty patches. If you dont take fixedValue, but zeroGradient on the inlet, it might move with the flow....Also nice, but you dont want that :-) Goodluck, Frank
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Frank Bos |
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#4 |
Member
Ralph
Join Date: Mar 2009
Posts: 40
Rep Power: 17 ![]() |
Thanks a lot Frank.
Ralph |
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#5 |
New Member
Malu
Join Date: Dec 2011
Posts: 1
Rep Power: 0 ![]() |
hey everyone, i was also stuck at simulating a pitching airfoil simulation, finally i was able to do so uisng sixDoFRigidBodyDisplacement. now i have to add a heaving motion along with the pitching motion. i first tried to do so it by changing the constraints (fixed axis and fixed line), but this did not work. does anyone have an idea about how to go about this?
Thanks Malu |
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#6 | |
Senior Member
Daniel WEI (老魏)
Join Date: Mar 2009
Location: Beijing, China
Posts: 689
Blog Entries: 9
Rep Power: 21 ![]() |
Quote:
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~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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#7 |
Senior Member
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 14 ![]() |
Hi every body
I did'nt understand what is value(0 0 0) in movingWallVelocity boundry condition????/ Can any one explain??? |
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#8 |
Senior Member
Artur
Join Date: May 2013
Location: Southampton, UK
Posts: 372
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#9 |
New Member
saurabh shubham
Join Date: Aug 2017
Posts: 7
Rep Power: 9 ![]() |
hi everyone.
I am using the same code for the case of heaving airfoil as I did use for transverse oscillating cylinder. but when I am checking the velocity at the tip of the airfoil at t=0, then the value is not zero, as in case of oscillating cylinder case. even after running it for few seconds the vorticity contours starts originating from the front of the airfoil. |
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#10 | |
New Member
Chayanit Nigaltia
Join Date: Jan 2018
Posts: 29
Rep Power: 8 ![]() |
Quote:
I am struck in piching airfoil case. Can you help me in this case?? |
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