hi, everyone. I am new to comsol. I want to make a simulation of measurement of absorption coefficients in standing wave tube;
here are my problem I encountered：
I don't how to add a plane sound wave to a closed wall boundary, I mean
I use a cuboid simulate the air in the tube, and all the surfaces are set hard sound boundary， but how to add a plane sound wave to the air？
i try to set a end surface of cuboid as [plane wave radiation]，and then add [incident pressure field] ,but then this surface is not hard sound boundary.
all I want is to simulate the 1th fig in www.acs.psu.edu/drussell/Demos/SWR/AbsorptionCoeff.pdf.
and here is my cuboid picture.
imgsrc.baidu.com/forum/w%3D580...f3bcda5dea0346f21fbe09aa4d.jpg
here are my problem I encountered：
I don't how to add a plane sound wave to a closed wall boundary, I mean
I use a cuboid simulate the air in the tube, and all the surfaces are set hard sound boundary， but how to add a plane sound wave to the air？
i try to set a end surface of cuboid as [plane wave radiation]，and then add [incident pressure field] ,but then this surface is not hard sound boundary.
all I want is to simulate the 1th fig in www.acs.psu.edu/drussell/Demos/SWR/AbsorptionCoeff.pdf.
and here is my cuboid picture.
imgsrc.baidu.com/forum/w%3D580...f3bcda5dea0346f21fbe09aa4d.jpg