This is a repository copy of Near-wall dynamics of inertial particles in dilute turbulent channel flows.

Hydrodynamic and viscoelastic interactions between turbulent fluid within a channel at and a polymeric phase are investigated numerically using a multiscale hybrid approach. Direct numerical simulations are performed to predict the continuous phase and Brownian dynamics simulations using the finitely-extensible nonlinear elastic (FENE) dumbbell approach are carried out to model the trajectories of polymer extension vectors within the flow. Impact on polymer stretching is discussed, with streamwise extension dominant close to the wall, and wall-normal extension driven by high streamwise gradients of wall-normal velocity. In this case, it is shown that chains already possessing high wall-normal extensions may attempt to orientate more in the streamwise direction, causing a curling effect. These effects are observed in instantaneous snapshots of polymer extension, and the effects of the bulk Weissenberg number show that increased leads to more stretched configurations and more streamwise orientated conformities close to the wall, whereas in the bulk flow and log-law regions, the polymers tend to trace fluid turbulence structures. Chain orientation angles are also considered, with demonstrating little influence on the isotropic distributions in the log-law and bulk flow regions. The effect of the polymer relaxation time on the turbulent drag reduction is discussed, with greater Weissenberg numbers leading to more impactful reduction. Finally, the velocity gradient tensor invariants are calculated for the drag-reduced flows, with polymers having a significant impact on the Q-R phase diagrams, with the presence of polymers narrowing the range of values in the wall regions and causing flow structures to become more two-dimensional.

This is a repository copy of Agglomeration dynamics in liquid-solid particle-laden turbulent channel flows using an energy-based deterministic approach.

This is a repository copy of Multiscale modelling of ceramic nanoparticle interactions and their influence on the thermal conductivity of nanofluids.

This study determines the thermophysical properties of nanofluids using ultrasonic techniques. Using an acoustic test cell, fitted with 4 MHz high-temperature transducers, measurements of the speed of sound in an aqueous dispersion of alumina nanoparticles (Al2O3, 99.9%, spherical, dp = 50 nm) are made at volume fractions from 1-5 vol% over the temperature range 20-90°C. The observed relationships between the measured parameters and speed of sound variation are presented. Available theoretical approaches are reviewed and applied to the data of the study. The speed of sound data together with measurements of density and predictions of thermal conductivity, derived from Lagrangian particle tracking (LPT) simulations, are used to determine