COMSOL 6.3: No Laminar Inflow boundary condition?

Please login with a confirmed email address before reporting spam

Hello,

How can I access the Laminar Inflow boundary condition in COMSOL 6.3?

I am working with the Laminar Flow module and I wish to apply a Laminar Inflow boundary condition to my inlet as per these youtube instructions (timestamp 6:40). However, in the drop-down menu, there is no Laminar Inflow, only Fully-developed Flow, which does not allow me to specify an Entrance pressure and Entrance Length.



1 Reply Last Post May 7, 2025, 4:09 a.m. EDT

Please login with a confirmed email address before reporting spam

Posted: 23 hours ago May 7, 2025, 4:09 a.m. EDT

Hello Zane,

In the documentation, in the Theory of laminar flow, a section "Fully Developed Flow (Inlet)" describes what you refer to. There is in V6.3 an automatic detection of the length L, instead of an arbitrary fixed value in older versions. If you want to access/modify this value L, expand the Inlet boundary condition to find the corresponding "Equation View" (you need to activate this possibility of viewing the details of the equations in the "Show more options" menu). You will find spf.inl1.L = 10sqrt(spf.inl1.intop(1)) in 3D, as it is described in the doc. The entrance pressure is renamed into average pressure in the context of the Fully Developed Flow, I believe this is better terminology. So it seems like the condition you are looking for has just improved a bit over time.

Hope this helps! Eric Favre

Hello Zane, In the documentation, in the Theory of laminar flow, a section "Fully Developed Flow (Inlet)" describes what you refer to. There is in V6.3 an automatic detection of the length L, instead of an arbitrary fixed value in older versions. If you want to access/modify this value L, expand the Inlet boundary condition to find the corresponding "Equation View" (you need to activate this possibility of viewing the details of the equations in the "Show more options" menu). You will find spf.inl1.L = 10sqrt(spf.inl1.intop(1)) in 3D, as it is described in the doc. The entrance pressure is renamed into average pressure in the context of the Fully Developed Flow, I believe this is better terminology. So it seems like the condition you are looking for has just improved a bit over time. Hope this helps! Eric Favre

Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.