[nnis09]

Hi everybody,

I'm doing simulation on sound reduction through closed cell porous media as a sample. The sample is placed in a middle of two tubes namely upstream and downstream. Each tubes has two microphones as to captured the pressure generated by a soundsourse/speaker at the upstream. I assumed that the pressure at the downstream should be lower than the pressure at the upstream due to resistance of the sample. However I got otherwise...

I used Ergun equation to calculate viscous resistance and inertial resistance of the porous sample, 1.9407e7 and 4465 each.

I run the model at 300Hz, using Static Pressure, I got the pressure in Pa at each point of the microphones..

Using the pressure value I calculated the Sound Pressure Level (SPL)..am I right..?

I got SPL at the upstream or in front of the sample is lower than the back of the sample or at the downstream....

Maybe someone can help me...TQ.