Experimental Study on Capillary Microflows in High Porosity Open-Cell Metal Foams.

Metal foams have been widely used in heat pipes as wicking materials. The main issue with metal foams is the surface property capillary limit. In this paper, a chemical blackening process for creating a superhydrophilic surface on copper foams is studied with seven different NaOH and NaClO solution concentrations (1.

Review and a Theoretical Approach on Pressure Drop Correlations of Flow through Open-Cell Metal Foam.

Due to their high porosity, high stiffness, light weight, large surface area-to-volume ratio, and excellent thermal properties, open-cell metal foams have been applied in a wide range of sectors and industries, including the energy, transportation, aviation, biomedical, and defense industries. Understanding the flow characteristics and pressure drop of the fluid flow in open-cell metal foams is critical for applying such materials in these scenarios. However, the state-of-the-art pressure drop correlations for open-cell foams show large deviations from experimental data.

Synthesis and Characterization of Molten Salt Nanofluids for Thermal Energy Storage Application in Concentrated Solar Power Plants-Mechanistic Understanding of Specific Heat Capacity Enhancement.

Molten salts mixed with nanoparticles have been shown as a promising candidate as the thermal energy storage (TES) material in concentrated solar power (CSP) plants. However, the conventional method used to prepare molten salt nanofluid suffers from a high material cost, intensive energy use, and laborious process. In this study, solar salt-AlO nanofluids at three different concentrations are prepared by a one-step method in which the oxide nanoparticles are generated in the salt melt directly from precursors.

Analysis of Capillary Flow in a Parallel Microchannel-Based Wick Structure with Circular and Noncircular Geometries.

Capillary flow in porous media is of great significance to many different applications including microfluidics, chromatography, and passive thermal management. For example, heat pipe has been widely used in the thermal management of electronic system due to its high flexibility and low thermal resistance. However, the critical heat flux of heat pipe is often limited by the maximum capillary-driven liquid transport rate through the wicking material.

Evolution of Microdroplet Morphology Confined on Asymmetric Micropillar Structures.

The design of topological features to control the spreading of liquid has been widely investigated. Micropillar structures, for example, can retain stable droplets on the tip by inhibiting the contact line from advancing over a sharp solid edge. The pinning behavior of droplets on noncircular pillars, however, has received little attention.

Investigation of the confinement effect on the evaporation behavior of a droplet pinned on a micropillar structure.

Evaporation of sessile droplet suffers from reduced evaporation rate due to the confinement of vapor diffusion imposed by the bottom substrate. However, it is possible to change the evaporation behavior of a droplet by suspending it from the bottom substrate, in particular, supporting the droplet on a micropillar. This is expected to enable diffusion transport in the downward direction that will subsequently enhance evaporative transport.

Porous micropillar structures for retaining low surface tension liquids.

The ability to manipulate fluid interfaces, e.g., to retain liquid behind or within porous structures, can be beneficial in multiple applications, including microfluidics, biochemical analysis, and the thermal management of electronic systems.