Computational fluid dynamics study of kaolin-water flow in a T-junction using a novel shear-thinning fluid model

A recently proposed shear-thinning fluid model that mimics the response of seemingly viscoplastic materials is evaluated in computational fluid dynamics simulations by studying the steady flow of a kaolin-water suspension in a 2D T-junction. The velocity profiles for the kaolin-water suspension are reported at the mid-length of the main channel and the root of the bifurcation (where recirculation is expected to appear). The velocity profiles of the proposed model are compared with those from conventional viscoplastic models (Bingham plastic model and the Herschel-Bulkley model) at low (=100) and high Reynolds number (=2000). The new model predicts a recirculation zone (at the inner edge of the bifurcation arm) that conventional models do not. The effect of the variation in the model parameters (alpha(1) and alpha(2)) on velocity profiles at low (=100) and high Reynolds numbers (=2000) is also documented. These indicate the disappearance of the recirculation zone at low Reynolds number as alpha(1) (equivalently, viscosity) increases, whereas the recirculation zone persists even for higher values of alpha(1) at high Reynolds number. Further, at low Reynolds number, the skewing of maximum velocity towards the outer edge of the bifurcation arm disappears as alpha(2) increases, whereas the skewing persists even at the highest value of alpha(2) used at the high Reynolds number.