Resolving Effects of particle Shape and Inertia in Scalar Transport

ended

When small, rigid particles are immersed in a turbulent fluid, they tumble, slip, concentrate and re-orientate themselves amidst a chaotic flow. Simultaneously, material or heat (passive scalars) may be transferred from the surface by convection and diffusion. Nature and engineering are replete with examples: planktonic osmotrophs absorb nutrients from turbulent ocean waters, and industrial processes grow crystals in agitated suspension, to name but two. Such particles are rarely ever spherical. Yet, present approaches overlook this, neglecting the convective transport mechanisms governed by shape and inertia and fail to predict their consequences, for example, in the adaptation strategies of marine diatoms. To address this problem, this project pairs a researcher with experience of fundamental turbulence physics from working in Germany with an expert in applied experimental fluid mechanics at a UK university, achieving a mutually beneficial exchange of knowledge. The Fellow will parametrically survey the effects of aspect ratio and inertia in the mass transfer to ellipsoidal particles, by reacting deformed ion-exchange resin beads in a turbulent solution to determine transport rates as a function of turbulence, fluid and particle properties. This will be followed by a detailed investigation of the underlying flow physics using state-of-the-art laser induced fluorescence and velocimetry techniques, allowing cause-and-effect mechanisms to be established between macro- and micro-scale effects. The project will target its dissemination activities at scientific communities where immediate impact is expected, including chemical and energy engineering and oceanography. This pairing and choice of project, together with the host’s capabilities and track record, will ensure successful completion of this ambitious research project and maximally support the Fellow’s career development.