Mathematical Model of the Acoustical Absorption Behaviour of the Open Cell Polyurethane Foams and Comparison With Experimental Results

Szary a Nwankwo normal absorption coefficient tortuoslty resistivity of the volume a of the equivalent cell in Nm s resistivity of the volume d of the equivalent cell in Nm s ratio of specific heats for air dynamic viscosity of the air = 1.84 x 10 kgm"s" (poiseville) bulk density of the foam in kgm 1 density of the air at normal conditions = 1.213 kg rn" density of the solid skeleton in kg m radian frequency = 21rf eppytssess