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 The information provided may be out of date.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.

Create time-averaged 2d surface plot

Please login with a confirmed email address before reporting spam

Hello everyone,
I’m trying to model a DBD plasma actuator using the DC discharge module. A sinusoidal signal of 5kV and 1kHz is applied to the electrode and a time dependent study is performed for 10 periods, from 0 to 10 ms. I’m able to create a 2D surface plot of the body force at different times, but I’m also interested to build a 2D surface plot of time-averaged body force (on a period). How can I do this?

Thanks

Chiara

3 Replies Last Post Mar 15, 2015, 4:04 p.m. EDT
Luke Gritter Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Feb 23, 2015, 5:36 p.m. EST
Chiara,

I'm not aware of a quick way of doing this for a large number of time steps within the GUI, but the easiest approach is probably just to use a series of "Join" operations (under Data Sets). Since you can only combine two solutions with a single Join operation, you will need to use as many Join operations as time steps you want to combine (minus one). Use the "General" method to enter an expression that divides each solution by the total number of time steps you are combining so that you will end up with an average solution.

--
Luke Gritter
AltaSim Technologies
Chiara, I'm not aware of a quick way of doing this for a large number of time steps within the GUI, but the easiest approach is probably just to use a series of "Join" operations (under Data Sets). Since you can only combine two solutions with a single Join operation, you will need to use as many Join operations as time steps you want to combine (minus one). Use the "General" method to enter an expression that divides each solution by the total number of time steps you are combining so that you will end up with an average solution. -- Luke Gritter AltaSim Technologies

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Mar 14, 2015, 11:05 a.m. EDT
Hello Chiara,

Now I'm also trying to model a DBD plasma actuator and I'm interested in the body force, too. Would you like to communicate with me so we can exchange ideas about these simulations?

My E-mail is bit.cc.ac@gmail.com.

Best regards,
Pan Chen
Hello Chiara, Now I'm also trying to model a DBD plasma actuator and I'm interested in the body force, too. Would you like to communicate with me so we can exchange ideas about these simulations? My E-mail is bit.cc.ac@gmail.com. Best regards, Pan Chen

Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Mar 15, 2015, 4:04 p.m. EDT
Hi,

To plot a time average, you can use the timeavg() operator as expression for the plot. There are several flavors of it, which you can look up in the documentation. The most basic is timeavg(t_start, t_end, quantity).

You may have to wait some time after you press the plot button, though. This is a very expensive operation.

Regards,
Henrik
Hi, To plot a time average, you can use the timeavg() operator as expression for the plot. There are several flavors of it, which you can look up in the documentation. The most basic is timeavg(t_start, t_end, quantity). You may have to wait some time after you press the plot button, though. This is a very expensive operation. Regards, Henrik

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.