A unified scaling model for flow through a lattice of microfabricated posts

Srivastava, Nimisha; Din, Changsong; Judson, A.; MacDonald, N.C.; Meinhart, Carl

doi:10.1039/b919942j

Cited by 54 publications

(54 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transient wetting behavior of the wick structure was shown to behave in accordance with Washburn dynamics [192], and the NST surface increased the wetting velocity. The vapor chamber was sealed along the edge by local laser welding to avoid heating the entire device to the necessary processing temperatures.…”

Section: Titanium Thermal Ground Plane (Ti-tgp)mentioning

confidence: 79%

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Weibel

Garimella

2013

Advances in Heat Transfer

View full text Add to dashboard Cite

Owing to their high reliability, simplicity of manufacture, passive operation, and effective heat transport, flat heat pipes and vapor chambers are used extensively in the thermal management of electronic devices. The need for concurrent size, weight, and performance improvements in high-performance electronics systems, without resort to active liquid-cooling strategies, demands passive heat spreading technologies that can dissipate extremely high heat fluxes from small hot spots. In response to these daunting application-driven trends, a number of recent investigations have focused on the design, characterization, and fabrication of ultra-thin vapor chambers for proximate heat spreading away from these hot spots. The predominant transport mechanisms and operational limits have been found to be different under these conditions relative to conventional low-power heat pipes. Noteworthy advances in the fundamental understanding of evaporation and boiling from porous microstructures fed by capillary action, and improvements in vapor chamber characterization, modeling, design, and fabrication techniques are reviewed. Characterization of evaporation and boiling from idealized and realistic wick structures, observation of vapor formation regimes as a function of operating conditions, assessment of fluid dryout limitations, design of novel multi-scale and nanostructured wicks for enhanced transport, and incorporation of these high heat flux transport phenomena into device-level models are discussed. These recent developments have successfully extended the maximum operating heat flux limits of vapor chambers.2

show abstract

Section: Titanium Thermal Ground Plane (Ti-tgp)mentioning

confidence: 79%

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Weibel

Garimella

2013

Advances in Heat Transfer

View full text Add to dashboard Cite

show abstract

“…21 Based on the Washburn law, Ishino et al 22 considered viscous dissipation on the substrate and the side walls, and obtained two extreme regimes for short and tall pillars, respectively. Then, Srivastava et al 23 and Xiao and Wang 24 developed Ishino's model and got a more accurate exponent. Taking account of the viscous dissipation in the triple-phase region, dynamic wetting in the early stage of a liquid film with/without bulk droplet and the entire drop footprint on pillar-arrayed surfaces were studied.…”

Section: -3mentioning

confidence: 99%

Dynamic spreading on pillar-arrayed surfaces: Viscous resistance versus molecular friction

2014

View full text Add to dashboard Cite

The dynamic spreading of a liquid droplet on micropillar-arrayed surfaces is experimentally investigated. A theoretical model is proposed to include energy dissipations raised from both the viscous resistance at mesoscale and the molecular friction at microscale in the triple-phase region. The scaling laws and spreading shape of the droplet change with the variation of the liquid viscosity because of the competition between these two mechanisms of energy dissipations at the moving contact line. The Laplace pressures at the interior corner and at the wavy contact line are the answers to the excess driving energy and the superwetting on pillar-arrayed surfaces. The formation and evolution of the bulk and the fringe are also analyzed in detail. Our results may help to understand the wetting dynamics on microtextured surfaces and assist the future design of engineered surfaces in practical applications. C 2014 AIP Publishing LLC. [http://dx

show abstract

“…Taking account of both the viscous resistance from the pillars and the substrate, Ishino et al did an elegant scaling analysis based on the Washburn law to obtain two extreme regimes for short and tall posts, respectively (Ishino et al 2007). Then, Srivastava et al (2010) and Xiao, Enright & Wang (2010) developed this model to be more accurate. However, while these studies all averaged the MCL to be a straight line (two-dimensional problem) or a circle (three-dimensional problem), the MCL is actually a complex curve (Courbin et al 2007) and requires a multiscale study.…”

Section: Introductionmentioning

confidence: 99%

Multiscale dynamic wetting of a droplet on a lyophilic pillar-arrayed surface

2013

View full text Add to dashboard Cite

Dynamic wetting of a droplet on lyophilic pillars was explored using a multiscale combination method of experiments and molecular dynamics simulations. The excess lyophilic area not only provided excess driving force, but also pinned the liquid around the pillars, which kept the moving contact line in a dynamic balance state every period of the pillars. The flow pattern and the flow field of the droplet on the pillar-arrayed surface, influenced by the concerted effect of the liquid-solid interactions and the surface roughness, were revealed from the continuum to the atomic level. Then, the scaling analysis was carried out employing molecular kinetic theory. Controlled by the droplet size, the density of roughness and the pillar height, two extreme regimes were distinguished, i.e. R ∼ t 1/3 for the rough surface and R ∼ t 1/7 for the smooth surface. The scaling laws were validated by both the experiments and the simulations. Our results may help in understanding the dynamic wetting of a droplet on a pillar-arrayed lyophilic substrate and assisting the future design of pillar-arrayed lyophilic surfaces in practical applications.

show abstract

A unified scaling model for flow through a lattice of microfabricated posts

Cited by 54 publications

References 9 publications

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Recent Advances in Vapor Chamber Transport Characterization for High-Heat-Flux Applications

Dynamic spreading on pillar-arrayed surfaces: Viscous resistance versus molecular friction

Multiscale dynamic wetting of a droplet on a lyophilic pillar-arrayed surface

Contact Info

Product

Resources

About