Author Topic: Unsteady flow and DPM  (Read 2087 times)

Offline moloy_kb

  • Newbie
  • *
  • Posts: 19
  • Reputation: +0/-0
  • Searching for solution
    • View Profile
Unsteady flow and DPM
« on: March 17, 2012, 10:46:10 AM »
Advertisement
I want to study the behavior of the particle under the unsteady flow. Consider a situation where the flow through a pipe in pulsatile in nature, say at the inlet to the pipe, the velocity is given as V=V_0*(1+sin(w*t)). If I solve the unsteady Fluent Solver, it will give the result, but what happens if I wants to solve the DPM along with this.
For, steady flow like V=V_0, first the eulerian flow field has to be solved, then we switch on  the DPM. Now, how to implement this in case of pulsatile problem.
Thanks in advance.

Offline admin

  • Administrator
  • Newbie
  • *****
  • Posts: 11
  • Reputation: +0/-0
    • View Profile
Re: Unsteady flow and DPM
« Reply #1 on: March 19, 2012, 06:33:42 PM »
You can solve the DPM as a steady state case within the transient simulation. In such a case the flow of fluid will be solved for each time step but after each time step, particles trajectories will be solved. But you can have the discrete phase in transient manner as well. In which the flow of DPM is also solved for each time step. The option is available in Fluent.

Offline moloy_kb

  • Newbie
  • *
  • Posts: 19
  • Reputation: +0/-0
  • Searching for solution
    • View Profile
Re: Unsteady flow and DPM
« Reply #2 on: March 21, 2012, 05:02:12 AM »
It means if I solve the unsteady DPM, then Fluent will solve the NS eqns. at every time step and according to that it will go the the Lagrangian tracking. If this is true, then whether there is any need to solve first the transient flow and then switch on the unsteady DPM. Pl. reply and thanks in advance.

Offline admin

  • Administrator
  • Newbie
  • *****
  • Posts: 11
  • Reputation: +0/-0
    • View Profile
Re: Unsteady flow and DPM
« Reply #3 on: March 21, 2012, 04:15:13 PM »
You dont need to solve the flow field before you switch to DPM. You can turn the DPM along with the flow field. When you see constant cross-sectional velocities or constant discrete phase propeties at the outlet, it means that the simulation is converged.