Air Permeability of Thick Foams: Flow Numerical Simulations

From measured data are determined permeability parameters of thick perforated foam samples, used as car seats cushions. Parameters are used for numerical flow simulations in foam samples. Model of detailed geometry gives good view about detailed flow field (pressure and velocity) in foam volume, influenced by perforations and grooves. However, simulated flow is several times different from measured one. The main flow is through perforations (99%) and flow through foam is of two orders lower. Using homogenous geometry with “averaged” permeability parameters, evaluated from measured values, the coincidence of measured and simulated flow is very good, difference of 1-5%. However, it is not possible to get any details of flow in foam volume. Using inlet layer, the flow is decreasing, first in perforations and the ratio between perforation and foam flows is more balanced.