Inclusion of DLVO forces in simulations of non-Brownian solid suspensions: Rheology and structure

The understanding of the rheological behaviour of suspensions in aqueous electrolytes is necessary for the optimal design of hydraulic transport lines. In these applications, particle size is at least 10 micron, and the particle Reynolds number, Re_p, is finite: O(10⁻¹). Although there are some experimental and numerical...

Numerical simulations of dense granular suspensions in laminar flow under constant and varying shear rates

Using an immersed boundary-lattice Boltzmann method, we investigated the response of dense granular suspensions to time-varying shear rates and flow reversals. The evolution of the relative apparent viscosity and particle structures was analysed. The concentration of solids (ϕ_v) and particle Reynolds numbers (Re_p) were...

On using variable molecular masses in multicomponent lattice Boltzmann simulations

The option of varying the molecular mass in multicomponent lattice Boltzmann simulations is being explored. First, results are presented for droplet formation at an aperture in a second immiscible liquid medium in which the difference in density between the two media is achieved by introducing asymmetry in the EOS, via adding particularly...

Shear thickening and history-dependent rheology of monodisperse suspensions with finite inertia via an immersed boundary lattice Boltzmann method

Three-dimensional direct numerical simulations of dense suspensions of monodisperse spherical particles in simple shear flow have been performed at particle Reynolds numbers between 0.1 and 0.6. The particles translate and rotate under the influence of the applied shear. The lattice Boltzmann method was used to solve the flow of the...

A lattice boltzmann approach to surfactant-laden emulsions

We present a pseudopotential lattice Boltzmann method to simulate liquid–liquid emulsions with a slightly soluble surfactant. The model is investigated in 2-D, over a wide parameter space for a single, stationary, immiscible droplet, and surface tension reduction by up to 15% is described in terms of a surfactant strength Λ (which roughly...

Simulating liquid droplets: A quantitative assessment of lattice Boltzmann and Volume of Fluid methods

While various multiphase flow simulation techniques have found acceptance as predictive tools for processes involving immiscible fluids, none of them can be considered universally applicable. Focusing on accurate simulation of liquid-liquid emulsions at the scale of droplets, we present a comparative assessment of the single-component...

The effect of pulsating pressure on the performance of a PEM fuel cell with a wavy cathode surface

In the context of attempts to improve the performance of Proton Exchange Membrane (PEM) fuel cells with a heterogeneous porous gas diffusion layer (GDL) consisting of carbon paper, we investigated whether - and to which degree - pulsating the pressure in a single waveform cathode channel affects the flow field in the channel and the...