Hi all,

I’m working on a CFD/PBM problem with only constant particle growth through a laminar flow reactor.

As far as I know, when particle growth is constant and occurs alone (no nucleation, no agglomeration and no breakage), the number of particles at outlet has to be exactly the same as inlet.

However, simulations on laminar flow reactor shows an increase in particle number i.e. there is somehow creation of particle in the reactor specially in near-wall zones. The number of particles at inlet is N=1.91e14 which increases to 2.55e14 at outlet

I tested this issue on an ideal plug flow reactor where there was no velocity profile and the particle number at inlet and outlet were exactly the same.

What I am trying to say is that, I think, the problem is not related to PBM algorithm and it arises when PBM is coupled with CFD.

So the question is what is the mechanism in fluent which makes this problem to occur?

My case study is:

2D-Axi (L=0.1(m) , D=0.006(m)), laminar, Eulerian mixture model, PBM model (Standard Method of Moments).

Boundary conditions: axis, velocity inlet, pressure outlet

Solution Method: Coupled

Spatial Discretization: moment: 2nd order upwind, volume fraction: Quick, Momentum: 2nd order upwind and pressure: Presto

Any comment would be highly appreciated.