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 DesmondM. August 8, 2019 10:15

Fluent wall motion specified in the form of array of velocity with corresponding time

I want to simulate a piston moving in a chamber.

I have the velocity of the piston as an array with corresponding time.
vel = [time1 vel1
time2 vel2
time3 vel3
...]

How can i specify this as a udf?
What precaution I need to follow when defining my time step here and in fluent while solving.

Thanks

 AlexanderZ August 8, 2019 21:18

ansys fluent customization manual

you may make 2 arrays:
time = {time1, time2, ... ,timen}
velocity = {vel1,vel2,...,veln}
size of arrays shoulb be same in this approach

check time and define velocity according to your time
part of code you may use
Code:

```temp_time = CURRENT_TIME; for (i=1;i<(sizeof(time)/sizeof(time[0]);i++) { if (temp_time>time[i-1] and temp_time<time[i])   velocity = vel[i-1]; }```
best regards

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