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Referring to Arguments/ Variables in UDF

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Old   March 3, 2022, 09:47
Default Referring to Arguments/ Variables in UDF
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Will Crawford-Jones
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Hello,



I'm creating my own UDF for 6-DOF contact. How do I refer to specific variables in my UDF? Specifically, i'm looking to refer to the components of my 6-DOF body's angular velocity, the components of my 6-DOF body' s velocity, the components of hydrodynamic torque applied to my 6-DOF body and the components of my hydrodynamic force applied to my 6-DOF body. I know i'm meant to refer to them near the top of my UDF and in the uclib.c file, but don't know the specific 'name' for these variables/ arguments. Please let me know where I can find a list.



I hope this make sense, please let me know if not.



Thanks



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Old   March 4, 2022, 06:25
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To give you a little more information. I have made separate reports of these four variables and therefore they exist as a field function too. I want to refer to them as a field function in my UDF.



In my uclib.c file I have included...



ucarg(calculateForce, "Cell", "$6-DOFBodyAngularVelocityyReport", sizeof(CoordReal[1]));

ucarg(calculateForce, "Cell", "$6-DOFBodyMomentyReport", sizeof(CoordReal[1]));

ucarg(calculateForce, "Cell", "$6-DOFBodyForcexReport", sizeof(CoordReal[1]));

ucarg(calculateForce, "Cell", "$6-DOFBodyForcezReport", sizeof(CoordReal[1]));

ucarg(calculateForce, "Cell", "$6-DOFBodyVelocityxReport", sizeof(CoordReal[1]));

ucarg(calculateForce, "Cell", "$6-DOFBodyVelocityzReport", sizeof(CoordReal[1]));



Near the top of my User Function I have included...



calculateForce(Real (*result)[3], int size, CoordReal (*position)[3],

unsigned int *bodyID, CoordReal (*bodyPosition)[3], CoordReal (*"$6-DOFBodyAngularVelocityyReport")[1], CoordReal (*"$6-DOFBodyMomentyReport")[1], CoordReal (*"$6-DOFBodyForcexReport")[1], CoordReal (*"$6-DOFBodyForcezReport")[1], CoordReal (*"$6-DOFBodyVelocityxReport")[1], CoordReal (*"$6-DOFBodyVelocityzReport")[1])



and a little lower down have ...



omega[0] = 0;

omega[1] = "$6-DOFBodyAngularVelocityyReport";

omega[2] = 0;


torque[0] = 0;

torque[1] = "$6-DOFBodyMomentyReport";

torque[2] = 0;


drag_force[0] = "$6-DOFBodyForcexReport";

drag_force[1] = 0;

drag_force[2] = "$6-DOFBodyForcezReport";


velocity[0] = "$6-DOFBodyVelocityxReport";

velocity[1] = 0;

velocity[2] = "$6-DOFBodyVelocityzReport";



i then refer to the variables as drag_force[0] etc.



However, when I try to compile I get the errors "error C2059: syntax error: 'string'" , "error C2090: function returns array" as well as some other errors. Any ideas how I should work with these variables?



Thank you
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Old   March 12, 2022, 09:41
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Will Crawford-Jones
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Star-CCM+ manual says "Field functions can be accessed in user functions by requesting them with their names enclosed in double- quotes; the syntax depends on whether they are scalar or vector field functions. Temperature would be referred to as “$Temperature”, for example, and velocity as “$$Velocity”. " And "Scalar field functions have CoordReal elemental type, even when the fundamental data that they represent has a different type." What I refer to above are scalars as they are the components of a vector.

Can any one provide help? Thanks in advance for any help you can provide.
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