RT Journal Article T1 Patterns and long range correlations in idealized granular flows A1 García Orza, José Antonio A1 Brito, Ricardo A1 Van Noije, T. P. C. A1 Ernst, M. H. AB An initially homogeneous freely evolving fluid of inelastic hard spheres develops inhomogeneities in the dow field u(r, t) (vortices) and in the density held n(r, t) (clusters), driven by unstable fluctuations, delta a = {delta n, delta u}. Their spatial correlations, (delta a(r, t)delta a(r', t)], as measured in molecular dynamics simulations, exhibit long range correlations; the mean vortex diameter grows as xi(t) proportional to root ln t; there occur transitions to macroscopic shearing states, etc. The Cahn-Hilliard theory of spinodal decomposition offers a qualitative understanding and quantitative estimates of the observed phenomena. When intrinsic length scales are of the order of the system size, effects of physical boundaries and periodic boundaries (finite size effects in simulations) are important. SN 0129-1831 YR 1997 FD 1997-08 LK https://hdl.handle.net/20.500.14352/58515 UL https://hdl.handle.net/20.500.14352/58515 LA eng NO © World Scientific Publishing Company. International Conference on Discrete Models for Fluid Mechanics (6. 1996. Boston). Two of us (R.B. and T.v.N.) acknowledge support of the foundation "Fundamenteel Onderzoek der Materie (FOM)", which is financially supported by the Dutch National Science Foundation (NWO). One of us (R.B.) acknowledges further financial support from Universidad Complutense through the program "Estancias Breves en el Extranjero" and DGICYT (Spain) number PB94-0265. One of us (M.H.E.) acknowledges support from the Offices of International Relations of Universidad Complutense and Universiteit Utrecht for his stay in Madrid. NO Fundamenteel Onderzoek der Materie (FOM) NO Dutch National Science Foundation (NWO) NO Programa Estancias Breves en el Extranjero (Universidad Complutense) NO DGICYT (España) DS Docta Complutense RD 9 abr 2025