Effect of Bubble Size on the Microbubble Drag Reduction of a Turbulent Boundary Layer

Kawamura, Takafumi; Moriguchi, Yasuhiro; Kato, Hiroharu; Kakugawa, Akira; Kodama, Y.

doi:10.1115/fedsm2003-45645

Cited by 15 publications

(6 citation statements)

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“…Furthermore, Xu et al [117] did direct numerical simulation of turbulent channel flow using small spherical bubbles of average void fraction of 8%. Their findings were consistent with Kawamura et al [108] that smaller bubbles produced sustained DR over time compared to larger bubbles. Larger bubbles only reduced drag for a short time before they increased drag.…”

Section: Microbubblessupporting

confidence: 86%

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Reviews on drag reducing polymers

Tiong

Perumal

2015

Korean J. Chem. Eng.

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Polymers are effective drag reducers owing to their ability to suppress the formation of turbulent eddies at low concentrations. Existing drag reduction methods can be generally classified into additive and non-additive techniques. The polymer additive based method is categorized under additive techniques. Other drag reducing additives are fibers and surfactants. Non-additive techniques are associated with the applications of different types of surfaces: riblets, dimples, oscillating walls, compliant surfaces and microbubbles. This review focuses on experimental and computational fluid dynamics (CFD) modeling studies on polymer-induced drag reduction in turbulent regimes. Other drag reduction methods are briefly addressed and compared to polymer-induced drag reduction. This paper also reports on the effects of polymer additives on the heat transfer performances in laminar regime. Knowledge gaps and potential research areas are identified. It is envisaged that polymer additives may be a promising solution in addressing the current limitations of nanofluid heat transfer applications.

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Section: Microbubblessupporting

confidence: 86%

“…Smaller bubbles with a diameter of 10 μm are known to be effective for DR [108], whereas larger bubbles with a diameter exceeding 500 μm tend to lose their DR efficiency [109]. These microbubbles can be produced in numerous ways, but the most common method is electrolysis.…”

Section: Microbubblesmentioning

confidence: 99%

Reviews on drag reducing polymers

Tiong

Perumal

2015

Korean J. Chem. Eng.

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“…Nanobubbles used in oxygen-rich drinking water treatment technology by using ceramics and carbon mixes to produce bubbles compliments the usage of reducing drag on a pipeline. Due to high effectiveness in reducing the resistance found in Kawamura et al, [9] finding to produce bubbles of 0.5 to 2 mm. However, to tackle the information to find the best method of using bubble drag reduction, the research conducted must conclude the previous finding of the bubble drag reduction method.…”

Section: Introductionmentioning

confidence: 97%

“…Based on the resulting representation, the research intended to use the first lubrication scheme to understand the extent to which nanobubble was involved in reducing drag in the flat plate experiment. Preliminary experiments Kawamura et al, [9] applied air bubbles with a diameter of 0.5 mm, which two times more effective than air bubbles with a diameter of 2 mm injected in the turbulent boundary layer.…”

Section: Introductionmentioning

confidence: 99%

Nanobubbles Interaction on Flat Plates Affecting Volumetric Gas Flux and Local Void Ratio

Yanuar

Gunawan

Utomo

2020

ARFMTS

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Distributing solution to the engine, cooling system, and ballast system are crucial for a ship to operate correctly. Drag is one of the obstructions in the internal flow of the pipeline, restricting the fluid to stream smoothly. Majority studies use numerous methods to reduce the effect, such as using microbubble, minimizing the length of pipe installation, and injection of nanobubble. Bubble drag reduction is one of the most modern methods; the previous study showed that 2mm bubble size has a lot less beneficial for decreasing drag than a 40 µm bubble at the same fluid velocity. Based on previous research, this study will show the impact of nanobubble in reducing drag produced by a carbon-ceramic nozzle. This research studies the nanobubble influence explicitly by using diverge types of conditions such as various injection distance, several areas of the plates, and analyze the utilization of nanobubble and microbubble within the boundary layer. The boundary layer investigated by circumscribing volumetric gas flux and gas flux injection and then scrutinize the findings providing a local void ratio. Research towards the boundary layer used a shred of photographic evidence, examine by using Jimage processing to view the distance between the exterior of the plates and the current generated by nanobubble injection. Flux ratio created from the resulting multiplier constant, which is the ß factor that expresses the effectiveness of the nanobubble drag reduction technique. Finally, the result obtained that nanobubble is 0.82912 times more efficient than using microbubble with an injection range of 80mm and a local void ratio of 2.1.

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“…McCormick and Battacharyya (1973) reported drag reduction of 10% to 30% with small bubbles generated by electrolysis, despite estimated mean void fractions in the boundary layer on the order of only 1%. Kawamura et al (2003) produced bubbles with two different methods: the first involved injecting air through a slot, producing bubbles from 0.5 to 2 mm in diameter. The second enlisted bubble formation through out-gassing to produce bubbles 1/10" to 1/100 t ' the size of the injected bubbles.…”

Section: Introductionmentioning

confidence: 99%

High Reynolds Number Micro-Bubble and Polymer Drag Reduction Experiments

Ceccio¹,

Dowling²,

Perlin³

et al. 2008

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Background: This effort was a continuation of the joint ONR and DARPA programs of the PI and Co-PI's initiated as part of the DARPA Friction Drag Reduction Program (ATO/TTO). The purpose of the investigation was to examine the physics and engineering of friction drag reduction methods for turbulent boundary layers (TBL) found in hydrodynamic flows. Three methods of friction drag reduction (FDR) were examined:" Polymer Drag Reduction-solutions containing extensible, long-chain molecules ' are injected into a TBL. The polymer molecules interact with the underlying turbulent flow and lead to a reduction of the correlated velocity fluctuations and, hence, a reduction of the turbulent transport of momentum across the TBL. This leads to local drag reduction of up to -70% for a TBL flow over smooth surfaces compared to a flow without polymer injection.* Micro-bubble Drag Reduction-air is injected into the TBL with the aim of producing a large volume of small bubbles in the near-wall region of the TBL. The presence of the bubbles reduces the bulk density of the fluid near the wall and possibly alters the turbulent velocity fluctuations. These effects can combine to locally reduce the friction drag over 80%." Air Layer Drag Reduction-air is injected into the TBL with the aim of creating a stable gas layer of very high void fraction (> 80% void fraction), separating the liquid flow from the solid surface. This results in friction drag reductions of over 80% compared to the friction drag of an unmodified TBL. DISTRIBUTION STATEMENT A 20080131 272 Approved for Public ReleaseDistribution UnlimitedThese FDR methods have been studied for some time on the laboratory scale, yielding a great deal of information on their engineering potential and underlying methods. However, the flow physics responsible for FDR does not easily scale from the laboratory to full-scale hydrodynamic applications. Hence, our effort focused on conducting a series of experiments at both large size scales and high Reynolds numbers in order to further explore the flow physics and practicality of these FDR methods.Our experiments were performed on a canonical TBL flow formed on a flat plate, zeropressure gradient boundary layer. The maximum length of the test model was -10 m, and the maximum velocity of the flow was -20 m/s, making the Reynolds number based on maximum length -200 million. Our experiments were conducted in the William B.Morgan Large Cavitation Channel (LCC), owed and operated by the Naval Surface Warfare Center-Carderock Division of the U. S. Navy.During this portion of our research program, three rounds of testing in the LCC were conducted:* Phase III (Polymer FDR) * Phase IV (MBDR/ALDR) * Phase V (Polymer FDR).Two additional rounds of testing were conducted under the first portion of ONR and DARPA support: Phase I was a baseline test of the model, and Phase II was on MBDR. Also, a portion of Phase V was devoted to examining the influence of roughness on Polymer FDR and ALDR. This portion of the effort was supported under DARPA contract "...

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Effect of Bubble Size on the Microbubble Drag Reduction of a Turbulent Boundary Layer

Cited by 15 publications

References 0 publications

Reviews on drag reducing polymers

Reviews on drag reducing polymers

Nanobubbles Interaction on Flat Plates Affecting Volumetric Gas Flux and Local Void Ratio

High Reynolds Number Micro-Bubble and Polymer Drag Reduction Experiments

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