Michael Yianneskis

Fluid mechanics; turbulence; fluid mixing; haemodynamics. Current research areas include: Fluid mixing in stirred reactors Small scale turbulence and dissipation Vortices and flow instabilities Optical microscopy and rheology studies of complex fluids Most of the above areas involve a combination of experiments using primarily if not exclusively optical measurement techniques and predictions using Computational Fluid Dynamics simulation methods. Fluid mixing research has been on-going at King's for over twenty years and both single and multi-phase flow processes have been studied. The work has included laser-sheet visualisation and laser- Doppler anemometry and PIV investigations of mean velocity and turbulence characteristics agitated by different impeller designs and/ or combinations of impellers. This work has been accompanied by measurements of the mixing time and of the power consumption. Novel impeller shapes have been designed at King's and manufactured using the Division's CAD/CAM facilities. CFD predictions of the flows have been made using a sliding-mesh approach around the impeller with a stationary mesh in the bulk of the tank: comparisons of these predictions with LDA measurements has shown excellent promise for the accurate determination of mixing characteristics in a 'virtual' mixer environment. Recent haemodynamics research has been concerned with novel aggregation indices developed to improve understanding of the relation of the aggregation characteristics of red blood cells with the rheology of blood. The research is aided by the availability of a state-of-the art complex fluids laboratory incorporating rheometers, interfacial tensiometers, atomic force microscopy and optical shearing microscopy.

Fluid mechanics; turbulence; fluid mixing; haemodynamics.