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 The information provided may be out of date.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.

intensity in acoustic

Please login with a confirmed email address before reporting spam

Re:
Hi

when you start with COMSOL try to use only 1 physics at the time, test yourmodel physics by physics, once you have got the 3 fundamental physics working alone (with fixed values for the interconnections) then mix two and finally 3, else you will take long and get confused. It's certainyl quicker, I still apply it, 6 years after my first COMSOL model, and when I believe I'll manage without this ways, then I loose a day ;)

basically if you use frequency domain solver, all driving loads are amplitudes at the frequency given by the solver step(s). Try a few Model Library axamples, and check the webinars on acoustics on the web

--
Good luck
Ivar
---------------------------------------
Hi Ivar
thanks for your reply
I tried Model Library examples, I started COMSOL by use 1 physics then I added 2 other physics. I want to know can I change intensity in my models?
this is very important for me.

Hoping for help,thanks very much!

feri

5 Replies Last Post 28.11.2012, 03:31 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.11.2012, 05:09 GMT-5
Hi

you can use values (numbers) in any field, but also equation and expressions, so you can define a variable entryy for the heat or temperture etc.

You might make your model nn linear though

--
Good luck
Ivar
Hi you can use values (numbers) in any field, but also equation and expressions, so you can define a variable entryy for the heat or temperture etc. You might make your model nn linear though -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.11.2012, 05:42 GMT-5
thanks Ivar

I defined external Q in bioheat equation :
Q=alfa*P^2/rho*c
that P is acoustic pressure
on the other hand I=P^2/rho*c
I cant chang "I" because its dependend on p !
I dont know what you mean!

thanks
Feri
thanks Ivar I defined external Q in bioheat equation : Q=alfa*P^2/rho*c that P is acoustic pressure on the other hand I=P^2/rho*c I cant chang "I" because its dependend on p ! I dont know what you mean! thanks Feri

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.11.2012, 06:24 GMT-5
Hi

I believe you need to explain a bit more, I probably misunderstood youre need

--
Good luck
Ivar
Hi I believe you need to explain a bit more, I probably misunderstood youre need -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.11.2012, 09:03 GMT-5
Hi

I want to simulate heat generation by ultrasound in tissue in different intensities and frequencies.
I mixed 3 physics for this purpose: acoustic pressure, piezo plane strain, bioheat equation.
is that true???
I have just a problem, I can't input my sightly intensity in this model!


thanks alot
Feri
Hi I want to simulate heat generation by ultrasound in tissue in different intensities and frequencies. I mixed 3 physics for this purpose: acoustic pressure, piezo plane strain, bioheat equation. is that true??? I have just a problem, I can't input my sightly intensity in this model! thanks alot Feri

Mads Herring Jensen COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 28.11.2012, 03:31 GMT-5
Hi Feri

If you have the possibility to upgrade to Comsol 4.3a your problem will be much easier to solve (but I believe the same procedure can be used in 3.5a). Here you first solve your acoustics and piezo problem, say in the frequency domain using the predefined Piezo-Acoustic Interaction interface. Then you solve a bio-heat-transfer problem where your heat source Q = alfa*P^2/rho*c gets the pressure from the alreaddy solved acoustics model.

Best regards
Mads
Hi Feri If you have the possibility to upgrade to Comsol 4.3a your problem will be much easier to solve (but I believe the same procedure can be used in 3.5a). Here you first solve your acoustics and piezo problem, say in the frequency domain using the predefined Piezo-Acoustic Interaction interface. Then you solve a bio-heat-transfer problem where your heat source Q = alfa*P^2/rho*c gets the pressure from the alreaddy solved acoustics model. Best regards Mads

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.