In this paper, the design, fabrication and experimental analysis of a piezoelectrically actuated micro squeeze flow rheometer is presented. Being only 30x30x0.5 mm in size, the micro rheometer is sensitive to very small volumes of the order of 1-10 nano-litre of liquid and light enough to operate at frequencies in the kHz regime, an order of magnitude higher than normally attainable with conven...

This paper discusses shear viscosity measurements of polymer melts by the capillary rheometer. Particular emphasis is placed on investigating the effects of viscous heating and pressure dependence of viscosity in capillary flows. The capillary flow problem is addressed by means of numerical simulation using the finite element method to solve the equations of continuity, momentum and energy alon...

Goldman, Joichi, and White proved a beautiful theorem showing that the falling factorial generating function for the rook numbers of a Ferrers board factors over the integers. Briggs and Remmel studied an analogue of rook placements where rows are replaced by sets of m rows called levels. They proved a version of the factorization theorem in that setting, but only for certain Ferrers boards. We...

Under specific conditions, rod-like cellulose nanocrystals (CNC) can assemble into structurally ordered soft glasses (SGs) with anisotropy that be controlled by applying shear. However, to achieve full structural control of SGs in real industrial processes, their response mixed shear and extensional kinematics needs determined. We hypothesise knowing the rheology CNC-based glass adopting a suit...

We investigate a variety of different polymer solutions in shear and elongational flow. The shear flow is created in the cone-plate-geometry of a commercial rheometer. We use capillary thinning of a filament that is formed by a polymer solution in the Capillary Breakup Extensional Rheometer (CaBER) as an elongational flow. We compare the relaxation time and the elongational viscosity measured i...

A novel method is presented for robustly simulating coupled dynamics in fluid–body interactions with vorticity-based flow solvers. In this work, the fluid dynamics are simulated with a viscous vortex particle method. In the first substep of each time increment, the fluid convective and diffusive processes are treated, while a predictor is used to independently advance the body configuration. An...

– We present a simple phenomenological model to describe shear-thickening in a wormlike micelle solution. The solution is assumed to undergo a reaction above a critical shear stress, to form a gel-like phase. There is no flow within this “gel” phase, and it is insoluble in the solution. The amount of gel in the system is determined by a competition between a stress-dependent reaction rate, whic...