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 The information provided may be out of date.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.
baffled duct - PML 3D PROBLEM
Posted 25.03.2014, 20:47 GMT-4 Acoustics & Vibrations, Mesh, Studies & Solvers Version 4.3b 1 Reply
Please login with a confirmed email address before reporting spam
I’d like to excite a cylindrical waveguide (rigid in one face and flanged in the other one) with a monopole located in M(x,y,z) and compute the pressure inside the duct. Also, compute the far field radiation within comsol 3D.
I used Comsol to validate my analytical code in the case of a cylindrical duct with different boundary conditions. The results are perfect unless all the walls are hard except the outlet which is flanged (=I use the radiation impedance formulation of a baffled piston in terms of struve and bessel functions). To model the infinite baffle, I employed 2 PMLs . The first one has the same radius of the main duct. The second with a bigger radius (I obtained sound pressure level results as shown in the attached screen shot 1.5 a , 2a, 5a) .Please find herewith the model as well (with PLM 2 Radius = 1.5a) . I applied five elements in the swept direction in the PMLs ( the PML scaling factor is 1).
Could you please let me know how to adapt the 3D PMLs to the problem inorder to get better results ?
Best regards.
Aniss
Hello Aniss Skalli
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.
Please login with a confirmed email address before reporting spam
and could you share you analytical solution script to me.
Hello every one,
I’d like to excite a cylindrical waveguide (rigid in one face and flanged in the other one) with a monopole located in M(x,y,z) and compute the pressure inside the duct. Also, compute the far field radiation within comsol 3D.
I used Comsol to validate my analytical code in the case of a cylindrical duct with different boundary conditions. The results are perfect unless all the walls are hard except the outlet which is flanged (=I use the radiation impedance formulation of a baffled piston in terms of struve and bessel functions). To model the infinite baffle, I employed 2 PMLs . The first one has the same radius of the main duct. The second with a bigger radius (I obtained sound pressure level results as shown in the attached screen shot 1.5 a , 2a, 5a) .Please find herewith the model as well (with PLM 2 Radius = 1.5a) . I applied five elements in the swept direction in the PMLs ( the PML scaling factor is 1).
Could you please let me know how to adapt the 3D PMLs to the problem inorder to get better results ?
Best regards.
Aniss