Numerical and experimental prediction of free surface flow of shear-thinning fluids

Abstract Within this study, a prediction of free surface flow during the gravity casting of shear-thinning fluids is of interest. An experimental test setup which enables analysis of the casting flow by means of optical measurements is designed and an in-house computational fluid dynamics solver based on the lattice Boltzmann method is implemented. The model of isothermal free surface flow of non-Newtonian incompressible fluid is considered. In particular, the study focuses on liquids which rheological properties can be idealised by the power-law model and its modifications. Parameters of the non-Newtonian models are identified based on the rheological measurements of the applied fluid samples. The gravity casting flow is examined both experimentally and numerically, while the experiments provide a reference set of data for validation of the implemented lattice Boltzmann algorithm. The computational results indicate that the algorithm is capable of resolving well the studied flow for computational grids with low spatial resolution.