Tayyib Can Bahadır
Hello i made an analyze for porous material to get absorbtion coifficent. I used Delany-Bazley model. 
I want to produce this material with 3d printer. My main material is PLA.
There is a forum about my study, I used that parameters to get absorbtion coifficent.
My problem is when i select port parameter i have a two option. First one is impedance tube when i choosed tube it worked and gave me a result. But the result is so unreal. 
After that i selected port parameter to porous material i take an warning. 
It says: The input power at the driven port is equal to zero. Please check the port definitions.
How can i solve this problem? 
And these are the results. Please help me