Rheology of a dilute suspension of spheres in a viscoelastic fluid under LAOS

Dilute suspensions of spheres in a viscoelastic liquid under oscillatory shear floware studied via numerical simulations. In linear viscoelastic regime, the 3D finite elementsimulation results agree with the analytical results from Palierne (1990).The analysis is extended to Large Amplitude Oscillations (LAOS). The rotation rate of thesphere as well as the bulk rheology are investigated. The moduli increase when particles are added into the fluid, in agreement with experimental findings. In the nonlinear range both moduli are found to be decreasing functions of the forcing amplitude. The non-linear response of the material is also illustrated by performing a Fourier analysis of the bulk shear stresssignal which shows the appearance of higher harmonic contributions.