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Old   July 24, 2018, 04:48
Unhappy External force 6DOF
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I have a very easy to picture 2D case. Two flat plates pushing together some fluid drop. One plate is stationary and the other is pressing with a constant force.

I have tried to solve it in two different ways.

The first, which should be the easier one, defining in fluent a spring only with a preload value. It didn't work.

On my second approach, I used the following UDF.

#include "udf.h"

DEFINE_SDOF_PROPERTIES(force_stamp, prop, dt, time, dtime)
	prop[SDOF_LOAD_F_X] = 0;
	prop[SDOF_LOAD_F_Y] = -500;
	prop[SDOF_LOAD_F_X] = 0;
	prop[SDOF_MASS] = 1;
	prop[SDOF_IXX]  = 0;
	prop[SDOF_IYY]  = 0;
	prop[SDOF_IZZ]  = 0;


   printf ("\n2d_test_box: Updated 6DOF properties");
I know that the dynamic mesh options are correct, because I already moved the wall with a velocity profile.

In both cases I defined a mass of 1 kg, because it gives an error with a mass of 0.

I hope somebody can give me a hand here.

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Old   April 22, 2019, 05:16
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Saif Ullah
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As a = F/m, putting m = 0 will obviously generate an error in calculating the translatory motion parameters.
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6dof, dynamic mesh, external force, fluent

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