Learning Forum

[2210912041_alamirsyah]

I do simulation airlift reactor using multiphase mixture and steady state any suggetion for looking fluids flow and gas holdup? 

[Rob]

I find plotting contours of phase to be useful. 

[2210912041_alamirsyah]

i am avoid transient becuase limitation on device and time. My question is can the airlift reactor solve on steady state? I was doing the simulation but it cant convergent, and the water got out to the outlet. But I have already set the outlet Vf_air to 1.

[Rob]

It depends on the what flow regime you're in. For a very transient bubbly flow you'll struggle, but a more dispersed system (ie sparger) might just converge. Note, you need to monitor points & flow field as well as residuals as the latter may not drop as per text book. 

The outlet volume fraction is for the back flow, if it's a pressure boundary anything reaching it will leave the domain. 

[2210912041_alamirsyah]

 

My goal in running this simulation is to examine the gas holdup and airflow under laminar flow conditions, given that the spangger inlet has a diameter of 8 cm and a velocity of 0.0249 m/s. Do I need to create a spangger with specific specifications, or is there another way to ensure the simulation is successful? Is there a way to make my simulation work, or do I still have to use a transient analysis? Also, should I split the reactor into two parts and simulate them just half of it to save on computational resources?

 

[2210912041_alamirsyah]

So i cant prevent water go out from my Airlift reactor? Or i just simulate the water and for the free surface no need?