4 research outputs found
: gradient-free, spontaneous and controllable droplet motion on soft solids
Most passive droplet transport strategies rely on spatial variations of
material properties to drive droplet motion, leading to gradient-based
mechanisms with intrinsic length scales that limit the droplet velocity or the
transport distance. Here, we propose droplet , a novel
mechanism that leverages an anisotropic fiber-reinforced deformable solid to
achieve spontaneous and gradient-free droplet transport. Using high-fidelity
simulations, we identify the fluid wettability and the fiber orientation as
critical parameters that enable controllable droplet velocity and long-range
droplet transport. Our results highlight the potential of fibrotaxis as a
droplet transport mechanism that can have a strong impact on self-cleaning
surfaces, water harvesting and medical diagnostics.Comment: updated references and revised pape
Numerical Solutions of a Gradient-Elastic Kirchhoff Plate Model on Convex and Concave Geometries Using Isogeometric Analysis
In this work, we study numerical solutions of a gradient-elastic Kirchhoff plate model on convex and concave geometries. For a convex plate, we first show the well-posedness of the model. Then, we split the sixth-order partial differential equation (PDE) into a system of three second-order PDEs. The solution of the resulting system coincides with that of the original PDE. This is verified with convergence studies performed by solving the sixth-order PDE directly (direct method) using isogeometric analysis (IGA) and the system of second-order PDEs (split method) using both IGA and C0 finite elements. Next, we study a concave pie-shaped plate, which has one re-entrant point. The well-posedness of the model on the concave domain is proved. Numerical solutions obtained using the split method differ significantly from that of the direct method. The split method may even lead to nonphysical solutions. We conclude that for gradient-elastic Kirchhoff plates with concave corners, it is necessary to use the direct method with IGA
On droplets that cluster and evaporate in reactive turbulence
This paper examines droplets that cluster and evaporate in reactive turbulence with direct numerical simulations. The flows are statistically homogeneous and isotropic with mass loadings of about 0.1, Stokes numbers of about 1, and Taylor-scale Reynolds numbers of about 40. Our simulation results reveal diffusion and premixed flames. When the mass loading is small or the Stokes number is large, clusters contain few droplets such that diffusion flames surround single droplets. However, when the mass loading is large or the Stokes number is small, clusters contain many droplets such that premixed flames propagate through clusters and diffusion flames surround clusters.ISSN:1070-6631ISSN:1089-7666ISSN:0031-917