Non-Newtonian behavior in simple fluids.
Using nonequilibrium molecular dynamics simulations, we study the non-Newtonian rheology of a microscopic sample of simple fluid. The calculations were performed using a configurational thermostat which unlike previous nonequilibrium molecular dynamics or nonequilibrium Brownian dynamics methods does not exert any additional constraint on the flow profile. Our findings are in agreement with experimental results on concentrated "hard sphere"-like colloidal suspensions. We observe: (i) a shear thickening regime under steady shear; (ii) a strain thickening regime under oscillatory shear at low frequencies; and (iii) shear-induced ordering under oscillatory shear at higher frequencies. These results significantly differ from previous simulation results which showed systematically a strong ordering for all frequencies. They also indicate that shear thickening can occur even in the absence of a solvent.
Delhommelle
Jerome
J
Equipe de Chimie et Biochimie Theoriques, UMR 7565, Universite Henri Poincare Nancy I, BP 239, F-54506 Vandoeuvre-les-Nancy, France. jerome.delhommelle@lctn.uhp-nancy.fr
Petravic
J
J
Evans
Denis J
DJ