I will present the results of Cold-Dark-Matter N-body simulations which include a hydrodynamic-like model of the coupling to the subresolution degrees of freedom. This model is similar to the Large-Eddy Simulations of turbulent flow. The results confirm the predictions of the theoretical analysis of the model, when available. Compared to standard N-body simulations, which neglect the dynamical influence of subresolution degrees of freedom, one finds a proliferation of small-mass halos, also in void regions, and a larger vorticity of the velocity field; the density profiles of high-mass halos still exhibit a cusp. The results agree with the trends observed in high-resolution N-body simulations. Thus, the hydrodynamic-like model provides a physical understanding of the mode-mode coupling in the hierarchical scenario of structure formation.