Learning Forum

[HusseinK]

Hello all,nI have a design of 3D room, 3 air inlets in the ceiling, 1 air outlet also in the ceiling (suction outlet), and a door where I open it and close it (open = pressure outlet, closed = wall).nNow I have introduced air coming from the ceiling inlets at a certain velocity.nFor the open door results, air particles residence time is much much higher than the closed door case, although it should be the opposite (I believe) as opening the door should help in discharging air faster.nnWhat could possibly be wrong?.Thank you, stay safen

[Karthik Remella]

Hello,nHow are you estimating your particle residence time? Are you using DPM? If so, what are your injections?nHow is your simulation convergence? Can you show a plot of the residuals and monitors here?nKarthikn

[Rob]

Also look at the flow field. Adding an extra boundary may have created a new flow feature that's responsible for the increased residence time. n

[HusseinK]

Hello Karthik,nI am using massless injection at the inlets faces, No DPM, am getting the residence time from the particle tracking using those massless injections, solution converged without problems.nnnI did not create any reports for this simulation.Thank you for the follow upn

[HusseinK]

Dear Rob,nnDo you mean in the BC's? they are defined as inlets, outlets, walls and that's it.nnLet me check the flow field and see if there is something that slipped out of my hand.Thanks againn

[Rob]

You opened the door: that's the extra boundary in the sense it allows air into or out of (most likely both) of the domain. n