access icon free Numerical simulations for the rheological characteristics of emulsions under several conditions including temperature, shear rate, surfactant concentration and droplet size

An emulsion system was simulated under simple shear rates to analyse its rheological characteristics using the lattice Boltzmann method. The relative viscosity of an emulsion under a simple shear flow along with changes in temperature, shear rate, surfactant concentration and droplet size was calculated. The relative viscosity of emulsions decreased with increase in temperature. The shear thinning phenomena explaining the inverse proportion between shear rate and viscosity were observed. An increase in the surfactant concentration caused an increase in the relative viscosity for a decane-in-water emulsion, because the increased deformation caused by the decreased interfacial tension significantly influenced the wall shear stress. An increase in droplet size caused a decrease in the relative viscosity and smaller shear thinning behaviour because of decreased aggregational and repulsive forces within the emulsion system.

Inspec keywords: shear strength; emulsions; drops; surface tension; water; viscosity; surfactants; rheology; shear flow; organic compounds; flow simulation; lattice Boltzmann methods; numerical analysis

Other keywords: emulsion system; surfactant concentration; deformation; lattice Boltzmann method; inverse proportion; droplet size; H2O; shear thinning; shear flow; numerical simulation; rheological characteristics; wall shear stress; shear rate; relative viscosity; decane-in-water emulsion; interfacial tension

Subjects: Numerical approximation and analysis; Viscosity of liquids; diffusive momentum transport; Fluid surface energy (surface tension, interface tension, angle of contact, etc.); Emulsions and suspensions; Rheology of fluids and pastes; General fluid dynamics theory, simulation and other computational methods; Multiphase flows; Mechanical properties of liquids

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