Pasty fluids modeling : a physicist point of view
complex fluids exhibit a yield stress : below some stress, they are
solid like, while above the flow. This plastic behavior is complex,
because the state in the absence of shear is not unique. In addition
and as a consequence, the yield stress fluids that are sensitive to
themral motions exhibit aging. I will describe how it is possible to
write simple models that take into accounts these coupled phenomena.