Experimental and theoretical work shows that the resonant frequencies of a liquid drop can be remotely controlled by the presence of a magnetic field, the latter driving the effective surface tension of the drop.

A reciprocal theorem for convective heat and mass transfer offers an alternative approach for calculating integrated quantities such as an average flux from a particle. The results for nonuniform boundary conditions are obtained via solutions of auxiliary problems with constant surface conditions.

The thermophoretic velocity of a colloidal sphere towards a solid boundary due to an imposed temperature gradient perpendicular to that wall is found by a systematic approach to be reduced from the corresponding value in the bulk by a factor $3(h/a)[\ln (a/h)+0.1087]$, in the limit where the particle-wall separation distance h is small compared with particle radius a. This corrects a previous result of $3(h/a)[\ln (a/h)-2.25$ produced by an $ad$ $hoc$ procedure.

Experiments reveal the dominant role of contacts on the loss of reversibility in sheared, viscous suspensions and a simple geometric model predicts the transition between reversible and irreversible dynamics.

In a model of attached wall eddies, eddies of the same height are, for the first time, kept apart by a minimum distance, resulting in better agreement with experimental observations, in particular for the flatness (kurtosis) of the streamwise velocity fluctuations.

In order to study diffusion and rheology within a spherical cavity, a theoretical framework is used to model the motion of an arbitrary number of hydrodynamically interacting colloidal particles confined within a solid, continuous spherical cavity. The model accurately accounts for many-body hydrodynamic interactions and lubrication interactions that occur between particles and with the cavity.

A model is developed to simulate the anti-rebound effect of the polymeric additives in the drop phase and shown to yield good qualitative agreement with the experimental observations.

Porous nematic microfluidics is shown to produce diverse fluid states –umbilic defect structures- which emerge as the result of backflow coupling between the flow shear and the fluid orientational field. Structures as diverse as square, triangular, rhombic and even Kagome lattices are found.

A systematic study of the effect of interface perm-selectivity reveals the four principal factors affecting hydrodynamic instability in concentration polarization at nonperfect interfaces.

The influence of the nutation angle on the precessing cylinder flow is investigated numerically. Three distinct regimes are encountered as the nutation angle is increased. Triadic resonances dominate at low angles, nonlinear interactions between the flow components involved in the resonance dominate at intermediate angles, and for large angles detuning together with stronger nonlinearity lead to chaotic flows dominated by boundary layer separations.

Experimental observations of the weakly nonlinear coupling of surface gravity waves and capillary waves show this coupling to be predominantly between collinear or nearly collinear waves.

The classic Faraday instability in a one-layer liquid film is extended to a two-layer film consisting of a lower liquid layer, supported by a vibrating solid plate, overlaid by a second layer of immiscible fluid with a free upper surface. A detailed analytical and numerical analysis of the linear stability of the film, and the interplay between the Faraday and the Rayleigh-Taylor instabilities, is presented.

Following Stokes’ “extremely easy” solution for Poiseuille flow in a circular pipe, Saint-Venant solved the analogous problem of beam torsion for arbitrary shapes. This paper explains the mathematics of unidirectional flow and applies it to some new problems, extending the number of analogies to seventeen.

The lattice-Boltzmann method is used to compute the flow of a particle suspension around obstacles, with attention given to the flow in the wake. Hydrodynamic interaction between particles in a many-particle suspension is shown to lead to exchange of particles between the wake zone and the free stream.

Multiple states in highly turbulent Taylor-Couette flow are found to be very robust for a large range of Taylor numbers and two different aspect ratios, and an unexpected antisymmetric roll state is observed.

A simple model represents Townsend’s attached eddy hypothesis in terms of an array of attached eddies, whose cumulative induction is responsible for the underlying velocity fluctuations in high-Reynolds-number wall turbulence.

Transition to turbulent in a pipe flow is investigated experimentally. The flow is analyzed using proper orthogonal decomposition, and it is found that the flow in the turbulent slugs closely resembles fully developed turbulence, and the flow in the intervening pseudo-laminar regions is governed by azimuthally steady traveling waves.

Large eddy simulation (LES) for practical engineering computations often requires reduced-order modeling of the near-wall turbulence. A new investigation assesses the capability of wall-modeled LES in predicting the space-time characteristics of wall-pressure and shear-stress fluctuations, which are important in applications including hydroacoustics, aeronautics, and structural vibration.