9312099 Weinstein This is a CRISP (Combined Research - industrial Sabbatical Program) proposal for a joint project between the CUNY City College and EXXON R&D. The main objective is experimental description of flow microstructure in two-phase gas-powder flow in high velocity fluidized beds. X-ray attenuation and pressure measurements will be made in a high velocity fluidized bed riser, a down-flow pipe, and gas jets into upflowing ga-solid mixtures. Normal stress within solid phase will be determined in a collapsing fluidized bed. The data on the mean and fluctuating velocities and solid fractions will be compared to available models. It is expected that the project will yield fundamental results on the flow structure in high velocity and bubbly fluidized beds, promote a micromechanical approach to understand the basic flow patterns, and construct a data base to calibrate CFD simulation codes. The interpretation of the fluctuating quantities, their correlations, power spectra, and turbulence length scales, will contributed to the validation of existing models. Better understanding of the basic flow mechanisms, as well as improved scale up and design methods of high velocity and bubbly fluidized beds are expected. ***
