Bioinspired surfaces for turbulent drag reduction

Golovin, Kevin; Gose, James W.; Perlin, Marc; Ceccio, Steven L.; Tuteja, Anish

doi:10.1098/rsta.2016.0189

Cited by 82 publications

(60 citation statements)

References 73 publications

(190 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Superhydrophobic surfaces(SHSs) are non-wetting surfaces consisting of hydrophobic chemical coating and micro-nano scale structures that lead to extremely high macroscopic contact angle ( 150 • ) and small contact angle hysteresis [1,2]. When submerged in liquid, micro-structures on SHSs can hold gas pockets which replace the contact area of liquid to solid elements with liquid to gas, causing slippage effect.…”

Section: Introductionmentioning

confidence: 99%

Effect of texture randomization on the slip and interfacial robustness in turbulent flows over superhydrophobic surfaces

Seo

Mani

2018

Phys. Rev. Fluids

View full text Add to dashboard Cite

Superhydrophobic surfaces demonstrate promising potential for skin friction reduction in naval and hydrodynamic applications. Recent developments of superhydrophobic surfaces aiming for scalable applications use random distribution of roughness, such as spray coating and etched process. However, most of previous analyses of the interaction between flows and superhydrophobic surfaces studied periodic geometries that are economically feasible only in lab-scale experiments. In order to assess the drag reduction effectiveness as well as interfacial robustness of superhydrophobic surfaces with randomly distributed textures, we conduct direct numerical simulations of turbulent flows over randomly patterned interfaces considering a range of texture widths w + ≈ 4−26, and solid fractions φ s = 11% to 25%. Slip and no-slip boundary conditions are implemented in a pattern, modeling the presence of gas-liquid interfaces and solid elements. Our results indicate that slip of randomly distributed textures under turbulent flows are about 30% less than those of surfaces with aligned features of the same size. In the small texture size limit w + ≈ 4, the slip length of the randomly distributed textures in turbulent flows is well described by a previously introduced Stokes flow solution of randomly distributed shear-free holes. By comparing DNS results for patterned slip and no-slip boundary against the corresponding homogenized slip length boundary conditions, we show that turbulent flows over randomly distributed posts can be represented by an isotropic slip length in streamwise and spanwise direction. The average pressure fluctuation on gas pocket is similar to that of the aligned features with the same texture size and gas fraction, but the maximum interface deformation at the leading edge of the roughness element is about twice larger when the textures are randomly distributed. The presented analyses provide insights on implications of texture randomness on drag reduction performance and robustness of superhydrophobic surfaces. arXiv:1709.05605v2 [physics.flu-dyn]

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of texture randomization on the slip and interfacial robustness in turbulent flows over superhydrophobic surfaces

Seo

Mani

2018

Phys. Rev. Fluids

View full text Add to dashboard Cite

show abstract

“…They may show reduced tendency toward fogging and icing due to the weak adhesion of water droplet on the surface . The presence of trapped air at the solid–water interface also reduces the hydrodynamic drag the surface experiences . When water flows near a flat surface, the velocity of water is zero at the solid surface (so called nonslip flow).…”

Section: Surface Engineering Through Texturingmentioning

confidence: 99%

“…It is not intended to be a comprehensive review. The readers are referred to several excellent reviews for in‐depth survey of the two research topics …”

Section: Introductionmentioning

confidence: 99%

DNA‐Based Nanofabrication: Pathway to Applications in Surface Engineering

Hui

Zhang

Deng

et al. 2019

Small

View full text Add to dashboard Cite

This Concept provides an overview of recent developments of DNA‐based nanofabrication and discusses its potential applications in the area of surface engineering. The first part of the paper discusses the strength and limitations of existing DNA‐based nanofabrication methods. The second part highlights several examples of surface engineering applications involving nano‐ and microscale surface textures. It finishes with a discussion of the opportunities and remaining challenges of applying DNA‐based nanofabrication in surface engineering applications.

show abstract

“…Superhydrophobic surfaces that extremely repel water have important value in many industrial applications, such as self‐cleaning, drag reduction, water‐oil separation, and anticorrosion, and can be also used as platforms or tools for droplet studies . Superhydrophobicity is always achieved with the aid of air trapped in the surface microstructure, forming the so‐called Cassie state, for which the surface design is very important .…”

Section: Introductionmentioning

confidence: 99%

A Dip‐Decoating Process for Producing Transparent Bi‐Superhydrophobic and Wrinkled Water Surfaces

Wang

et al. 2018

Adv Materials Inter

View full text Add to dashboard Cite

As mechanical strength is required in most applications using superhydrophobic surfaces, much effort has been applied toward enhancing this property. However, mechanical weakness can also be useful, but little attention has been focused on this seemingly undesirable feature. Here, using a sol–gel SiO2 coating as a weak surface, a dip‐decoating phenomenon is demonstrated to occur when immersing and withdrawing the coating from water. As a result, part of the coating's outer layer of nanoparticles (NPs) is peeled off by shearing motions of the three‐phase line, generating a bi‐superhydrophobic surface constructed by adjacent pristine and dipped areas, with different colors, adhesive forces, and compositional stabilities. Such a Janus surface, which also features ultrahigh transmittance due to antireflection, can be used as a peculiar multifunctional platform for droplet manipulations. The dip‐decoating technique also works as a distinctive way for introducing particles onto water surface, in which the density and distribution of peeled NPs can be adjusted by multi‐dipping processes. The wrinkled water surface, caused by high NP density, can be used with the Langmuir–Blodgett coating technique and have potential in fundamental studies, such as the evaporation of coated liquids.

show abstract

Bioinspired surfaces for turbulent drag reduction

Cited by 82 publications

References 73 publications

Effect of texture randomization on the slip and interfacial robustness in turbulent flows over superhydrophobic surfaces

Effect of texture randomization on the slip and interfacial robustness in turbulent flows over superhydrophobic surfaces

DNA‐Based Nanofabrication: Pathway to Applications in Surface Engineering

A Dip‐Decoating Process for Producing Transparent Bi‐Superhydrophobic and Wrinkled Water Surfaces

Contact Info

Product

Resources

About