Viscoelastic behaviour of fluids with steeply repulsive potentials

Powles, J.G.; Heyes, D. M.

doi:10.1080/00268970050032774

Cited by 38 publications

(46 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The scaling property was first noticed in the MD simulation results of Powles and collaborators [1,2,3,4]. In that work a phenomenological crossover function ∝ 1/ cosh(τ √ 2) has been used, which decays exponentially.…”

Section: Scaling Forms In Soft Sphere Fluids a Force Autocorrelatmentioning

confidence: 99%

“…Moreover, the r−integration can be carried out because the operator T + contains a factor δ (d) (r − σσ). Consequently χ = g (2) (σ+) is the hard sphere pair correlation function at contact. The remaining integrals are d−dimensional generalizations of the collision integrals as appearing in the Enskog theory for hard sphere fluids (See Chapter 16.8 of Ref.…”

Section: Time Correlation Functions For Hard Spheres Fluids a Ementioning

confidence: 99%

“…Consequently the pair distribution function g (2) (r) can be replaced by its value at contact, χ ≡ g (2) (σ+). The analysis is now reduced to a one body problem in the soft sphere potential.…”

Section: Scaling Forms In Soft Sphere Fluids a Force Autocorrelatmentioning

confidence: 99%

“…This work is motivated by the recent series of molecular dynamics studies of the same problem by Powles and co-workers [1,2,3,4]. They consider a steeply repulsive potential of the form v(r) = ǫ(σ/r) ν with exponent 12 ≤ ν ≤ 1152.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Exact short time dynamics for steeply repulsive potentials

Dufty

Ernst

2004

Molecular Physics

View full text Add to dashboard Cite

The autocorrelation functions for the force on a particle, the velocity of a particle, and the transverse momentum flux are studied for the power law potential v(r) = ǫ(σ/r) ν ( soft spheres). The latter two correlation functions characterize the Green-Kubo expressions for the self-diffusion coefficient and shear viscosity. The short time dynamics is calculated exactly as a function of ν. The dynamics is characterized by a universal scaling function S(τ ), where τ = t/τ ν and τ ν is the mean time to traverse the core of the potential divided by ν. In the limit of asymptotically large ν this scaling function leads to delta function in time contributions in the correlation functions for the force and momentum flux. It is shown that this singular limit agrees with the special Green-Kubo representation for hard sphere transport coefficients. The domain of the scaling law is investigated by comparison with recent results from molecular dynamics simulation for this potential.

show abstract

Section: Scaling Forms In Soft Sphere Fluids a Force Autocorrelatmentioning

confidence: 99%

Section: Time Correlation Functions For Hard Spheres Fluids a Ementioning

confidence: 99%

Section: Scaling Forms In Soft Sphere Fluids a Force Autocorrelatmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exact short time dynamics for steeply repulsive potentials

Dufty

Ernst

2004

Molecular Physics

View full text Add to dashboard Cite

show abstract

“…The normalized temperature PDF becomes narrower with increasing SV. For the pressure, 64 , after some rearrangement,…”

Section: Probability Distribution Functions For Subvolumesmentioning

confidence: 99%

Equilibrium fluctuations of liquid state static properties in a subvolume by molecular dynamics

Heyes

Dini

Smith

2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

System property fluctuations increasingly dominate physical process as the sampling volume decreases. The purpose of this work is to explore how the fluctuation statistics of various thermodynamic properties depend on the sampling volume, using molecular dynamics (MD) simulations. First an examination of various expressions for calculating the bulk pressure of a bulk liquid are compared, which includes a decomposition of the virial expression into two terms, one of which is the Method of Planes (MOP) applied to the faces of the cubic simulation cell. Then an analysis is made of the fluctuations of local density, temperature, pressure and shear stress as a function of sampling volume (SV). Cubic and spherical shaped SVs were used within a spatially homogeneous LJ liquid at a state point along the melting curve. It is shown that the MD-generated probability distribution functions (PDFs) of all of these properties are to a good approximation Gaussian even for SV containing only a few molecules (∼ 10), with the variances being inversely proportional to the SV volume, Ω. For small subvolumes the shear stress PDF fits better to a Gaussian than the pressure PDF. A new stochastic sampling technique to implement the Volume Averaging definition of the pressure tensor is presented, which is employed for cubic, spherical, thin cubic and spherical shell SV. This method is more efficient for less symmetric SV shapes.2

show abstract

Liquids at positive and negative pressure

Heyes

2008

Physica Status Solidi (b)

View full text Add to dashboard Cite

A Molecular Dynamics simulation study has been carried out of the Lennard–Jones fluid in the stable liquid and metastable liquid–vapour co‐existence regions. The interest has been mainly in states for which the pressure of the fluid is negative, and how they compare with those at positive pressure. The behaviour of the LJ fluid shows parallels with that of water, with the maximum tensile strength near the triple point being approximately seven times the critical pressure. The maximum tensile strength increases with cooling. Many of the properties, such as elastic moduli, show a smooth transition across the liquid–vapour boundary, on the liquid side, and a monotonic variation in the metastable region of the phase diagram. There is however a similarity in behaviour of combinations of the mechanical properties and the equation of state; for example, the pressure and infinite frequency Poissons ratio have minima at approximately the same densities. Insights into the heterogeneity of the assembly of particles are provided by probability distributions of the net force on a molecule and that of a definition for the local pressure experienced by a molecule, or ‘pressurelet'. The maximum negative pressure coincides with the maximum fraction of molecules individually experiencing a negative pressure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Viscoelastic behaviour of fluids with steeply repulsive potentials

Cited by 38 publications

References 19 publications

Exact short time dynamics for steeply repulsive potentials

Exact short time dynamics for steeply repulsive potentials

Equilibrium fluctuations of liquid state static properties in a subvolume by molecular dynamics

Liquids at positive and negative pressure

Contact Info

Product

Resources

About