Falk, K.K.FalkSavio, D.D.SavioMoseler, M.M.Moseler2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26141610.1103/PhysRevLett.124.1055012-s2.0-85082561276Viscosities 𝜂 and diffusion coefficients 𝐷𝑠 of linear and branched alkanes at pressure 0 <𝑃 <0.7  GPa and temperature 𝑇=500-600  K are calculated from molecular dynamics simulations. Combining Stokes-Einstein, free volume, and random walk concepts results in an accurate viscosity model for the considered 𝑃 and 𝑇. All model parameters (hydrodynamic radius, random walk step size, and step frequency) are extracted from equilibrium molecular dynamics via microscopic ensemble averages rendering 𝜂⁡(𝑃,𝑇) a parameter-free predictor for lubrication simulations.enbrownian motioncomplex fluidsdiffusiondissipative dynamicsinterparticle interactionslubricationRandom Walksrheological propertiesrheologyself-diffusiontribology620530journal article