simulating wing motion of an insect???

sanjay · January 17, 2012, 23:25

Hi, I am trying to simulate the motion of a insect wing (uniaxial motion i.e just rotation) in CCM+. I have selected the following physical conditions.

Morpher
3 dimesnsional
implicit unsteady
constant density
segregated flow
gas
turbulent
K-epsilon model

Can nay one tell me how to specify motion for the wing.

regards
www.aerosapien.blogspot.com

ping · February 13, 2012, 02:17

simple next step - create a field function which specifies the rotation velocity of the wing as a function of radius - eg using a sin function and a local cylindrical coordinate system. then for the wing change morpher setting to grid velocity and apply the field function.
we are promised overset mesh is version 7.02 coming soon and this will make this case faster to solve since the morpher adds another set of equations to solve.

sanjay · February 13, 2012, 03:27

thanks for the reply, Il work on it and get back for more discussion

regards
www.aerosapien.blogspot.com

ryancoe · February 16, 2012, 08:41

You could also create a field function, as ping suggests, but use the rotation and translation motion module to move the entire domain. This would be less computationally intensive than morphing the mesh.

Ryan

abdul099 · February 18, 2012, 07:26

Ryan, he needs to morph the mesh since not all of the domain will rotate. Just the wing will do the rotation while the body won't.

Sanjay, you can also directly apply a motion as boundary condition for the morpher. That's much easier than creating a field function specifying the grid velocity etc.
I agree to ping that overset mesh (once it's released, should be at beginning of march) will be a better approach, since morphing sometimes needs much more computing time than the flow solver and needs a significant amount of memory, especially on big meshes.

ryancoe · February 18, 2012, 09:54

Didn't realize there was a body involved. Good catch!

sanjay · March 6, 2012, 01:53

thanks a lot for those replies.
I decided that I will first do 2D simulation of flapping and then go for 3D

Can any one tell me how to create the flapping in 2D

regards
www.aerosapien.blogspot.com

alireza_b · May 11, 2012, 06:44

Hi
Dear users.
I write a UDF for flapping wing for fluent and compiled it and dont have any problem.
But i can not use dynamic mesh?
can you help me.
1- in gambit creat a zone aroud airfoil and implement a interface boundary condition.
2- in fluent i use define-interface
3- enable dynamic mesh with layering and smoothing.
4- selected airfoil and use UDF.
But airfoil is fixed and dont move!
albeit:
fluent have this error:
cg motion is incorrect.

abdul099 · May 11, 2012, 17:40

alireza_b, this is the star-ccm+ forum.

February 13, 2012, 02:17		#2
ping Member Ping Join Date: Mar 2009 Posts: 78 Rep Power: 5	simple next step - create a field function which specifies the rotation velocity of the wing as a function of radius - eg using a sin function and a local cylindrical coordinate system. then for the wing change morpher setting to grid velocity and apply the field function. we are promised overset mesh is version 7.02 coming soon and this will make this case faster to solve since the morpher adds another set of equations to solve. sanjay likes this.

February 16, 2012, 08:41		#4
ryancoe Member Ryan Coe Join Date: Jun 2010 Posts: 36 Rep Power: 3	You could also create a field function, as ping suggests, but use the rotation and translation motion module to move the entire domain. This would be less computationally intensive than morphing the mesh. Ryan __________________ Ryan Coe Aerospace & Ocean Engineering Department Virginia Tech website: http://filebox.vt.edu/users/ryancoe

February 18, 2012, 09:54		#6
ryancoe Member Ryan Coe Join Date: Jun 2010 Posts: 36 Rep Power: 3	Didn't realize there was a body involved. Good catch! __________________ Ryan Coe Aerospace & Ocean Engineering Department Virginia Tech website: http://filebox.vt.edu/users/ryancoe

May 11, 2012, 17:40		#9
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 431 Rep Power: 7	alireza_b, this is the star-ccm+ forum. __________________ We do three types of jobs here: GOOD, FAST AND CHEAP You may choose any two! Last edited by abdul099; May 12, 2012 at 07:10.

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February 13, 2012, 03:27		#3
sanjay Member aerosapien Join Date: Sep 2010 Posts: 49 Rep Power: 3	thanks for the reply, Il work on it and get back for more discussion regards www.aerosapien.blogspot.com

February 18, 2012, 07:26		#5
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 431 Rep Power: 7	Ryan, he needs to morph the mesh since not all of the domain will rotate. Just the wing will do the rotation while the body won't. Sanjay, you can also directly apply a motion as boundary condition for the morpher. That's much easier than creating a field function specifying the grid velocity etc. I agree to ping that overset mesh (once it's released, should be at beginning of march) will be a better approach, since morphing sometimes needs much more computing time than the flow solver and needs a significant amount of memory, especially on big meshes.

May 11, 2012, 06:44		#8
alireza_b New Member alireza Join Date: Jul 2009 Posts: 7 Rep Power: 3	Hi Dear users. I write a UDF for flapping wing for fluent and compiled it and dont have any problem. But i can not use dynamic mesh? can you help me. 1- in gambit creat a zone aroud airfoil and implement a interface boundary condition. 2- in fluent i use define-interface 3- enable dynamic mesh with layering and smoothing. 4- selected airfoil and use UDF. But airfoil is fixed and dont move! albeit: fluent have this error: cg motion is incorrect.

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