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Create time-averaged 2d surface plot

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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 15.03.2015, 16:04 GMT-4
Luke Gritter Certified Consultant

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Posted: 9 years ago 23.02.2015, 17:36 GMT-5
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

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Posted: 9 years ago 14.03.2015, 11:05 GMT-4
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

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Posted: 9 years ago 15.03.2015, 16:04 GMT-4
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

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