(399c) On Robert Brodkey, suspending solids and transporting slurries

Without a proper understanding of the fundamentals of turbulence and fluid-particle interactions, designing or debottlenecking processes involving suspensions and slurries is hopelessly risky. This statement may be a good summary of Robert Brodkey’s conviction and his sturdy message to all chemical engineers. In his lifelong career, Robert significantly contributed to advancing the state of the art at the interfaces of fluid mechanics, turbulence, multi-phase flows and chemical engineering. While, typically, Robert harboured a sound suspicion against modern computational tools such as computational fluid dynamics techniques and lattice Boltzmann modelling, these tools do increase our insights in e.g., liquid-solid and other multi-phase flows. Two examples will be highlighted by reviewing recent research results with respect to (a) the role of turbulence in suspending solid particles from the base of a stirred vessel and (b) the role of repulsive forces (electric double layers) in making up the effective viscosity of dense caustic slurries.