High energy tail in the velocity distribution of a granular gas

Abstract

The Enskog-Boltzmann equation for a homogeneous freely evolving system of smooth hard disks colliding inelastically is solved by means of the direct simulation Monte Carlo method. The distribution function shows an exponential high velocity tail, while it is Gaussian for small velocities. The numerical results are compared with recent predictions of approximate analytical theories and quite good agreement is found.

Computer simulation of uniformly heated granular fluids

“…(5) This behavior was already confirmed in Ref. [9] for d = 2 and has now been confirmed by our simulation results for d = 3.…”

“…[20] that Φ ǫ (c) ∼ c 2 log c for large c, which differs from the behavior (42) that has been confirmed here and in Ref. [9]. It is possible that the high energy tail obtained from the perturbative approach presented in Ref.…”

Gaussian kinetic model for granular gases

“…For small velocities the representation (13) applies with c (α) given by Figure 1 shows a comparison of the coefficient c G1 (α) with that for the Maxwell model given by (21). They are seen to be similar for weak dissipation but the Gaussian model grows more rapidly with increasing dissipation.…”

Enskog theory for polydisperse granular mixtures. II. Sonine polynomial approximation

“…Strictly speaking, such an assumption is valid only for perfectly elastic spheres in equilibrium [41]. Numerous experimental, theoretical, and simulation studies of inelastic, monodisperse systems have indicated that the distribution function departs from Maxwellian [42,43,44,45,46,47,48,49]. For the case of perfectly elastic mixtures, an estimate of the impact of this effect is given by Willits and Arnarson [6], who compare the shear viscosity predictions of two theories with that of MD simulations.…”