Menu

Discussion Forum

New Discussion
Filtra

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

How do you set a global definition as a boundary condition?

Posted 3 nov 2014, 18:02 GMT-5 Heat Transfer & Phase Change, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.4 1 Reply

Fintan Healy
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

HI, firstly I would like to say I am quite new to COMSOL so sorry if the answer to this question is very simple......

For my project I have built a simplistic 2d axis-symmetric geometry (effectively forming a cylinder) and on the top surface I want to define the net inward heat flux as a function of time.

Firstly I have defined a global interpolation function that describes the variation of heat flux with time and have named this function "qt".

Next I have set the boundary condition on the top surface as a general inward heat flux, but I cannot figure out how to define q0 as the function qt(t)

any help would be much appreciated!

Attachments:

1 Reply Last Post 4 nov 2014, 19:22 GMT-5
Steve Conrad
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 4 nov 2014, 19:22 GMT-5
At first glance, it appears you have set up the boundary condition correctly. The red color of the int1(t) function suggests you have inconsistent units. To verify this, click on the textbox, and hold the mouse over it to look at the error message. If that is the problem, then you may have to apply a unit operator in the boundary condition, or to set up the correct units in the function definition.

--
Steven Conrad, MD PhD
LSU Health
At first glance, it appears you have set up the boundary condition correctly. The red color of the int1(t) function suggests you have inconsistent units. To verify this, click on the textbox, and hold the mouse over it to look at the error message. If that is the problem, then you may have to apply a unit operator in the boundary condition, or to set up the correct units in the function definition. -- Steven Conrad, MD PhD LSU Health

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.

Suggested Content