Resistance/Reactance of porous materials for diffraction reduction

[thadman]

It is intuitively obvious that porous materials possess both a resistive component and a reactive component. Higher density materials often reflect high frequency content, but absorb more low frequency content. Lower density materials possess a lower amplitude high frequency reflection, but absorb less energy.

If we knew the specific damping capacity of the porous material, could we calculate the resistance/reactance wrt frequency?

Thanks,
Thadman

[bjorno]

Originally Posted by thadman

It is intuitively obvious that porous materials possess both a resistive component and a reactive component. Higher density materials often reflect high frequency content, but absorb more low frequency content. Lower density materials possess a lower amplitude high frequency reflection, but absorb less energy.

If we knew the specific damping capacity of the porous material, could we calculate the resistance/reactance wrt frequency?

Thanks,
Thadman

Hi Thadman,

A good start is to investigate complex acoustic absorbtion/transmission and reflexion measurement using a Kundts tube and deduce the equations at:


http://lva.insa-lyon.fr/download/bancs_kundt_en.pdf

b

[bjorno]

Hi,

This document might be of help too:

http://www.microflown.com/data/2006_Jasa_Lanoye.pdf

b

[thadman]

Originally Posted by bjorno

Hi Thadman,

A good start is to investigate complex acoustic absorbtion/transmission and reflexion measurement using a Kundts tube and deduce the equations at:


http://lva.insa-lyon.fr/download/bancs_kundt_en.pdf

b

Thanks