Effect of wall surface wettability on collective behavior of hydrogen microbubbles rising along a wall

Kitagawa, Atsuhide; Denissenko, Petr; Murai, Yuichi

doi:10.1016/j.expthermflusci.2016.08.010

Cited by 12 publications

(7 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, we cannot use even smaller bubbles to enhance heat transfer because a different phenomenon involving wettability takes place in the proximity of the wall. As we reported in a previous paper [19], we found that small bubbles, especially microbubbles, readily adhere to a vertical wall with poor wettability (Fig. 1).…”

Section: Introductionsupporting

confidence: 49%

Effect of heated wall inclination on natural convection heat transfer in water with near-wall injection of millimeter-sized bubbles

Kitagawa

Denissenko

Murai

2017

International Journal of Heat and Mass Transfer

Self Cite

View full text Add to dashboard Cite

A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. ABSTRACT Natural convection heat transfer from a heated wall in water with near-wall injection of millimeter-sized bubbles is studied experimentally. Velocity and temperature measurements are conducted in the near-wall region. In the range of the heated wall angles from 0 to 40˚ from the vertical, the heat transfer coefficient increases by up to an order of magnitude with bubble injection. The ratio of the heat transfer coefficient with bubble injection to that without injection increases with the wall inclination angle. Based upon measured liquid temperature distributions and liquid flow velocity profiles, enhancement of heat transfer by bubble injection is explained by two mechanisms. First, wall-parallel transport of cold liquid into the thermal boundary layer is enhanced by the bubbledriven flow. Second, wall-normal mixing of warm liquid and cold liquid occurs, as a result of wall-normal velocity fluctuations of the liquid phase activated by a combination of bubble rising motion, vortex shedding from the bubbles, and unsteady vortices formed within the boundary layer. The unsteady vortices travel along the wall together with the bubbles, primarily contributing to the enhancement of heat transfer at higher wall inclination angles.

show abstract

Section: Introductionsupporting

confidence: 49%

Effect of heated wall inclination on natural convection heat transfer in water with near-wall injection of millimeter-sized bubbles

Kitagawa

Denissenko

Murai

2017

International Journal of Heat and Mass Transfer

Self Cite

View full text Add to dashboard Cite

show abstract

“…Related to this matter, an interesting study is the one developed by Kitagawa et al [85], where the author focused on the effect of wettability on the movement and behavior of swarms of hydrogen bubbles that rise close to plates placed vertically inside a water tank made of acrylic. The bubbles are generated by electrolysis, and move through two different vertical areas of a test plate made of acrylic, one inclined at 3 • , so bubbles rise close to the wall, where a metal plate is placed, and the other is vertical and fully transparent, so the size of bubbles is measured once they exit the inclined area.…”

Section: Surface Wettability and Microbubble Drag Reductionmentioning

confidence: 99%

Micro/Bubble Drag Reduction Focused on New Applications

García-Magariño

Lopez-Gavilan

Sor

et al. 2023

JMSE

View full text Add to dashboard Cite

Bubble drag reduction has been shown to be a promising technique for reducing the drag in ships, thus reducing the emission of pollutants and allowing the compliance with the new requirements imposed recently in this respect. Different searches have been conducted in the publications related to this technique, and an increase in interest has been shown, especially in the last decade. In this context, a review of the experimental work related to bubble drag reduction published in the last decade is presented in the present article. The works were classified according to the facility used (towing tank, cavitation tunnel, water channel, Taylor–Couette…), and the main finding are presented. It was found that two new trends in research have arisen, while there are still contradictions in the fundamental basis, which needs further study.

show abstract

“…At 132 min, the volume of water had increased significantly near the vessel wall. This phenomenon can be explained by the "wall effect" (i.e., the porosity near the wall is larger than in the internal space 30 ), which caused N 2 to preferentially penetrate channels packed by porous media near the vessel wall. From 132 to 230 min, MH decomposed continuously and liquid water channels extended from the bottom to the top of the FOV parallel to the direction of N 2 injection.…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

Analyzing the Process of Gas Production from Methane Hydrate via Nitrogen Injection

Zhang

Kuang

Zhang

et al. 2017

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The application of air or nitrogen injection to extract natural gas from hydrates has attracted considerable attention because air and nitrogen are abundant; however, few studies have considered the relatively new method. This study employed magnetic resonance imaging to investigate the characteristics of hydrate dissociation via N2 injection. The results show that methane hydrate dissociation using N2 injection can be divided into three main stages: free gas and water liberation, hydrate dissociation driven by chemical potential differences, and restriction of hydrate dissociation due to increased resistance to N2 diffusion and a decreased contact area between N2 and hydrate. Various factors associated with the N2 injection method were considered, including injection rate and hydrate saturation. Furthermore, a comparison of recovery:injection ratio and methane cumulative production ratio to the results of hydrate dissociation via depressurization suggests that during low-hydrate saturation exploitation, N2 injection has advantages over the depressurization method.

show abstract

Effect of wall surface wettability on collective behavior of hydrogen microbubbles rising along a wall

Cited by 12 publications

References 33 publications

Effect of heated wall inclination on natural convection heat transfer in water with near-wall injection of millimeter-sized bubbles

Effect of heated wall inclination on natural convection heat transfer in water with near-wall injection of millimeter-sized bubbles

Micro/Bubble Drag Reduction Focused on New Applications

Analyzing the Process of Gas Production from Methane Hydrate via Nitrogen Injection

Contact Info

Product

Resources

About