Learning Forum

[shal3391]

Hi,

I am running a DPM injection of water into a 3D domain using a plain orifice single phase atomiser. However the DPM parcels are just hovering at the injection point as shown in the attached figure. WHat could be some possible reasons for this?

Thanks

[Rob]

How many time steps have you run? n

[shal3391]

Nearly 100 now, but the time step has reduced to 1e-08, which is the lower limit of my adaptive time-step criteria. n

[shal3391]

This is the injection area at 10,000 time steps. Despite having a high flow rate, the particles aren't injecting properly, with a very low velocity.n

[Amine Ben Hadj Ali]

What does the particle summary tell? Also please test with 2020R2.n

[Rob]

What does the flow field look like in that area? n

[Amine Ben Hadj Ali]

How does the pressure field look in that region?n

[shal3391]

Hi, I have attached velocity and pressure contour plots on the xy plane of my domain, I have also attached the mesh of the walls in my domain. I notice that the pressure plot looks odd, as if my boundaries between cell regions is influencing the pressure.nnn

[shal3391]

I have used 2020R1 and gotten the same result. nParticle summary: Advancing DPM injections ....nnumber tracked = 105534, escaped = 0, aborted = 0, trapped = 0, evaporated = 0, incomplete = 0, incomplete_parallel = 0, shed = 0n

[Rob]

The odd bit there is that you have interior labels set as walls, can you check you've not turned the cell facets into walls somewhere. The DPM tracks make sense for transient particles as they're not going anywhere they've not really done anything. If you turn off transient on the particles what does the plot look like? n

[Amine Ben Hadj Ali]

pressure field is odd. Check what Rob suggested. The plain orifices require reasnoable total pressure at the injection position to work its algorithm.n