Discrete phase two way coupling method.

- February 9, 2020 at 12:20 pm
  
  anshs
  Subscriber
  
  In reference to the Fluent theory guide: 16.16.5. Under-Relaxation of the Interphase Exchange Terms
  
  *Text copied from Documentation removed by Abenhadj
  
  So in the second option where new source terms are being updated once every flow iteration. what is the point of calculating particle source terms every DPM iteration? Do we store and update these values as well? (using the relaxation factor).
  
  How the values of each iteration of the 'particle source term' being used to calculate the new source term? using this equation:
  
  .
  
  Thanks.
- February 10, 2020 at 6:40 am
  
  Amine Ben Hadj Ali
  Ansys Employee
  
  The option is required for unsteady state and desired for steady state to keep the number of iterations required to have the full source load small.
- February 10, 2020 at 7:29 pm
  
  anshs
  Subscriber
  
  Yes, even for unsteady-state! I think particle source term is represented as 'Fcalculated' in the above-mentioned eq.
  
  Particle source term at iter1 = s1.
  Particle source term at iter2 = s2.
  
  How are s1 and s2 related?
  
  How do we update the particle source term 'Fcalculated' after every iteration?
- February 11, 2020 at 6:17 am
  
  Amine Ben Hadj Ali
  Ansys Employee
  
  Yes. That is the particle source term from particle tracker calculated every time particle trajectories are performed
- February 11, 2020 at 8:59 am
  
  anshs
  Subscriber
  
  1. So, basically we will be calculating updating Fnew at every flow iterations and Fcalculated at every DPM iteration, so how does this help the Unsteady simulation anyway?
  
  2. Also please answer how the momentum from the discrete phase is sent to the continuous phase! Is it directly sent as a source term to the momentum equation as 'Fnew' and before every flow iteration?
- February 11, 2020 at 9:31 am
  
  Amine Ben Hadj Ali
  Ansys Employee
  
  1/Reducing the number of continuous phase iterations to get the correct load: more in the help
  
  2/Check the documentation carefully: it also describes how that term looks alike. If nothing is shared in the documentation then we won't comment on that here.
- February 11, 2020 at 4:41 pm
  
  anshs
  Subscriber
  
  It would've been really helpful if you had mentioned the document's index number! Because I've been looking for it for a while now and couldn't find it!
  
  Thanks