  A cell method is developed, which takes into account the bubble geometry of
polyhedral foams, and provides for the generalized Rayleigh-Plesset equation
that contains the non-local in time term corresponding to heat relaxation. The
Rayleigh-Plesset equation together with the equations of mass and momentum
balances for an effective single-phase inviscid fluid yield a model for foam
acoustics. The present calculations reconcile observed sound velocity and
attenuation with those predicted using the assumption that thermal dissipation
is the dominant damping mechanism in a range of foam expansions and sound
excitation frequencies.
