RESUMO
This work aims at bridging experimental and numerical approaches to determine the optimal operating parameters for the fabrication of well-shaped polyvinylpyrrolidone (PVP) particles via electrohydrodynamic atomization. Particular emphasis is given to the role of the PVP solution viscosity. Solutions of PVP at various concentrations dissolved in Dimethylformamide (DMF) were prepared and analyzed. Numerical simulation using a coupled electro-CFD model was used to determine the ranges of experimental flow rate and the voltage, ensuring that well-shaped spherical particles are produced. It was deduced that the optimal combination of the parameters (flow rate, voltage, and polymer concentration) can be well approximated by a scaling law. The established relationship allowed determination of a stability island that guarantees that the given polymer solution will form spherical particles. Analyzing morphology and sizes of the particles manufactured in the optimal parameters range, we show, among others, that the size of the PVP particles can be predicted as a function of the flow rate by a power scaling relationship.
RESUMO
In the present work, we perform numerical simulations of the fluid flow in type B aortic dissection (AD), accounting for the flexibility of the intimal flap. The interaction of the flow with the intimal flap is modeled using a monolithic arbitrary Lagrangian/Eulerian fluid-structure interaction model. The model relies on choosing velocity as the kinematic variable in both domains (fluid and solid) facilitating the coupling. The fluid flow velocity and pressure evolution at different locations is studied and compared against the experimental evidence and the formerly published numerical simulation results. Several tear configurations are analyzed. Details of the fluid flow in the vicinity of the tears are highlighted. Influence of the tear size upon the fluid flow and the flap deformation is discussed.
