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 The information provided may be out of date.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.

Analytic expression

Siva Mahesh Tangutooru

Please login with a confirmed email address before reporting spam

Dear,

I want to write an expression for sine wave which is time dependent. The parameters are the amplitude is 3, duration of the wave is 0.1 milliseconds and the frequency of waves is 150 Hz. I tried to write it as 3*sin(2*pi*150[1/s]*t), but this gives me 150 sine waves of 6.66 millisecond duration per second. But I want 150 sine waves per second with duration of 0.1 mSec with zero amplitude between the waves. Can you please help me. I did attached a jpeg file to show what I needed. I appreciate your support. Thank you.


4 Replies Last Post Mar 19, 2014, 9:11 a.m. EDT

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Mar 19, 2014, 4:00 a.m. EDT
Hi!

You may use some combined analytic functions like this...

Ralf
Hi! You may use some combined analytic functions like this... Ralf


Siva Mahesh Tangutooru

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Mar 19, 2014, 5:13 a.m. EDT
Thank you for your support. But, I could not really understand the upper limit of x = 1.5/freq in analytic function. I mean this value effect on the waveform. My main intention is have the x value maximum of 0.05, which means I want sine waves of 0.1E-3 duration with 150 hz frequency for the 0.05 time period. The model which you sent me has the total time period of 0.01 (1.5/freq), but when I change it gradually to 0.05, the waveforms are changing wildly with their amplitudes. Is there any other combination function to produce similar result. If you can observe from your model, the amplitude is dampened. Please help me. Thank you.
Thank you for your support. But, I could not really understand the upper limit of x = 1.5/freq in analytic function. I mean this value effect on the waveform. My main intention is have the x value maximum of 0.05, which means I want sine waves of 0.1E-3 duration with 150 hz frequency for the 0.05 time period. The model which you sent me has the total time period of 0.01 (1.5/freq), but when I change it gradually to 0.05, the waveforms are changing wildly with their amplitudes. Is there any other combination function to produce similar result. If you can observe from your model, the amplitude is dampened. Please help me. Thank you.

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Mar 19, 2014, 7:43 a.m. EDT
Hi!
Try the second version.
Ralf
Hi! Try the second version. Ralf


Siva Mahesh Tangutooru

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Mar 19, 2014, 9:11 a.m. EDT
Thank you Ralf. It worked and understood the logic behind it.

Thank you Ralf. It worked and understood the logic behind it.

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.