The energy dissipation behavior of foams depending on changes of loading rate input has been investigated and simulated to provide and guide a safe car interior design for occupant protection. However, all used foam models obtained from experiments at a specific loading rate could not represent general mechanical behavior of foam for various loading rates. In this study, a porous elastic theory was applied to investigate the effect of fluid phase on apparent rate dependent behavior in the elastic range of an open-cell foam. The porous elastic parameters of a polyurethane foam filled with air and liquid were measured and estimated using a new experimental method and reported data. Then, the porous elastic behavior of the foam in a uniaxial stress condition was simulated using the porous elastic parameters for various loading rates. The model predictions for both air and liquid cases at the faster and slower strain rates showed a good agreement to the experimental results in the undrained and drained conditions. These results suggest that general elastic behavior of open-cell foams could be analyzed using the porous elastic theory.