Learning Forum

[Thodorisdm]

Dear, 

I have a question regarding the data structure of TP_VEL0, which in the UDF manual is defined as the location where the particles data is saved at the beginning of the timestep or at the entrance of the cell. 

Moreover, in the UDF example of a particle reflection at a boundary which uses the DEFINE_DPM_BC macro, after calculating the normal velocity of the particle and assigning it to the current particle velocity TP_VEL it also assigns it in TP_VEL0. My questions is why is the last assignment taking place? 

I think this is because you need the TP_VEL and TP_VEL0 at every timestep to calculate particle's acceleration. Thus, it assigns the reflected velocity of the particle to TP_VEL0 as well because this value is going to be used as the initial velocity at the next flow timestep. Is it correct?

Last but no least, the particle time TP_TIME(tp) is the particle residence time?

Kind regards, 

Thodoris

[Rob]

Have a look in https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v232/en/flu_udf/flu_udf_DPMDEFINE.html    DEFINE_DPM_BC Example 1.  

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v232/en/flu_udf/flu_udf_DataAccessMacros.html%23flu_udf_ApplicationMacros