© 2014 American Physical Society. The bulk viscosity of cosmological fluid and the creation of cold dark matter both result in the generation of irreversible entropy (related to dissipative processes) in a homogeneous and isotropic universe. To consider such effects, the general cosmological equations are reformulated, focusing on a spatially flat matter-dominated universe. A phenomenological entropic-force model is examined that includes constant terms as a function of the dissipation rate ranging from μ=0, corresponding to a nondissipative ΛCDM (lambda cold dark matter) model, to μ=1, corresponding to a fully dissipative CCDM (creation of cold dark matter) model. A time-evolution equation is derived for the matter density contrast in order to characterize density perturbations in the present entropic-force model. It is found that the dissipation rate affects the density perturbations even if the background evolution of the late universe is equivalent to that of a fine-tuned pure ΛCDM model. With increasing dissipation rate μ, the calculated growth rate for the clustering gradually deviates from observations, especially at low redshifts. However, the growth rate for low μ(less than 0.1) is found to agree well with measurements. A low-dissipation model predicts a smaller growth rate than does the pure ΛCDM model (for which μ=0). More detailed data are needed to distinguish the low-dissipation model from the pure ΛCDM one.