Learning Forum

[lisa555]

Hello, nI use the DPM to inject the particles into the system.nIf I would like to know the Saffman Lift Force on particle each time step.nI try to write the lift force model into code and report the value?nWhich MACRO should I use to output the value, is it one of DEFINE_DPM_LAW or DEFINE_DPM_BODY_FORCE?.Thanks,nLisan

[Amine Ben Hadj Ali]

If you want to get the applied value in Fluent you need unfortunately to do that manual say by coding the force and applying it into a DEFINE_DPM_BODY_FORCE and store into particle user variable. Be careful here: forces coded done in this way are not considered for two-way coupling. You might for that reason use DEfINE_DPM_SOURCE or Scalar update to just store the force value for post-processing without returning it back to Fluent.n

[lisa555]

Dear DrAmine,nThanks for your reply, below equation is Saffman's Lift Force from Theory Guide. nI would like to know the d_lk and d_kl meaning in the equation, and which code I could use in the Fluent Customization Manual to feat theam.nAppreciate for your reply.nLisan

[Rob]

From looking at the manual it's likely to be the deformation tensor, the model is described in more detail in the two references noted in 16.2.1.8 of the Fluent Theory Guide. n