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Ansys Free Student Software

Problems implementing liftforce using DEFINE_DPM_BODY_FORCE UDF

    • Nicholas Alberg
      Subscriber

      I'm currently trying to model particle migration in inertial microfluidics. I am therefore trying to implement the wall-induced and shear-gradient lift forces on the particles via a UDF, as these forces are not included in Fluent. My problem is that when using DEFINE_DPM_BODY_FORCE, the added force must be returned in cartesian coordinates. As I'm working with complex channel geometries (spiral, serpentine, ...), this is not easily done. Does anyone with experience with DPM UDF's know how I could achieve this?

      I was thinking that I could start with the cell the particle is currently in, to then find the cells at the channel walls in the same channel cross-section. I could then use the coordinates of the cells at the channel walls to define the angle I need to calculate the cartesian components of the forces. Since I have very limited experience with C, I'm not sure how to program this, so any advice would be very welcome.

      Any other suggestions different from the idea above are certainly also welcome!

       

      Thanks in advance

    • Surya Deb
      Ansys Employee

      Hello, 

      Do you have the correlations that you want to use? Can these correlations be provided as cartesian components?

      Regards,

      SD

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