Saturday, September 22, 2012

Tutorial: Solving a 2D Box Falling into Water

The purpose of this tutorial is to provide guidelines and recommendations for setting up and solving a dynamic mesh (DM) case along with the six degree of freedom (6DOF) solver and the volume of fluid (VOF) multiphase model. The 6DOF UDF is used to calculate the motion of the moving body which also experiences a buoyancy force as it hits the water (modeled using the VOF model). Gravity and the buoyancy forces drive the motion of the body and the dynamic mesh This tutorial demonstrates how to do the following:
  • Use the 6DOF solver to calculate motion of the moving body
  • Use the VOF multiphase model to model the buoyancy force experienced by the moving body
  • Set up and solve the dynamic mesh case
  • Create TIFF files for graphic visualization of the solution
  • Post-process the resulting data

This tutorial assumes that you are familiar with the menu structure in FLUENT and that you have a good understanding of the basic setup and solution procedures. Some basic steps in the setup and solution procedure will not be shown explicitly

Problem Description
The schematic of the problem is shown in Figure 1. The tank is partially filled with water. A box is dropped into the water at time t = 0. The box is subjected to a viscous drag force and a gravitational force. When the box is immersed in water, it is also subjected to a buoyancy force.

The walls of the box undergo a rigid body motion and will displace according to the calculation performed by the 6DOF solver. Whenever the box and its surrounding boundary layer mesh are displaced, the mesh outside of the boundary layer will be smoothed and/or re-meshed.


  1. Hi. I'm a student that study Fluent.
    It's a wonderful tutorial..!!
    I wanna information about VOF, 6DOF, dynamic mesh..etc..So..
    Please, send me this case file and Tutorial guide..
    Please, help me. Thanks !!
    email :

  2. hi,
    i have problem with udf moving box..
    i don't understand how to make it.
    so,, please, send me this file udf..
    this is my email

  3. Can you send some more details about this tutorial to my mail

  4. I would love to have the details for setting up this. Thanks.

  5. can you please send me this tutorial my mail :

  6. Can you please help me how you defined your volume fraction for air and water to get this pictures? Thanks my email address is

  7. Can you send f les (6dof-mesh.msh.gz and 6dof 2d.c) of this project to my email adress

  8. Can you send f les (6dof-mesh.msh.gz and 6dof 2d.c) of this project to my email adress

  9. Can you send f les (6dof-mesh.msh.gz and 6dof 2d.c) of this project to my email adress

  10. Can you please send me this tutorial my e-mail?
    Thanks. (

  11. Can you please send the tutorial case and mesh files if you have them, I would great help my research

  12. Could you send the mesh files?

  13. Could you send the mesh files?(6dof-mesh.msh.gz and 6dof 2d.c)
    thank you

  14. hi, i am doing research on two phase flow, tutorial is very interesting and helpful.can you please send udf 6dof_2d.c to me at i shall be highly obliged. thanks a lot.

  15. please sent case file mesh to

  16. please sent case file mesh to

  17. please send me the files

  18. please one of you send me the file at