Drag reduction by various micro-grooves in a rotating disk system

Wen, Suping; Wang, Wenbo; Wu, Shuhuai

doi:10.1177/0957650919827214

Cited by 5 publications

(2 citation statements)

References 33 publications

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“…This evolution in surface type in order to reduce drag between opposing surfaces (in this case, ice and its bed) also occurs elsewhere in the geological realm, as well as on man‐made manufactured surfaces undergoing relative motion and frictional wear, as was first emphasized by Pike (2001). Microforms described as elliptical “dimples,” “bumps” and grooves directly akin to their glacially eroded counterparts are cut on frictionally worn man‐made surfaces (Bai & Bai, 2014; Kim et al, 2005; Mo et al, 2013; Nosonovsky & Bhushan, 2007; Stelmakh et al, 2014; Wen et al, 2020). Moreover, individual forms are organized into different “functional surfaces” that evolve in response to different loads, velocities, and changing frictional drag.…”

Section: Discussion: Ice Sheet Beds As Glaciotribological Systemsmentioning

confidence: 99%

LiDAR‐based semi‐automated mapping of drumlins and mega‐scale glacial lineations of the Green Bay Lobe, Wisconsin, USA: Ice sheet beds as glaciotribological systems

Eyles

Bukhari

Sookhan

et al. 2022

Earth Surf Processes Landf

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A machine learning methodology for processing and visualizing high-resolution LiDAR digital data is used to map drumlins and mega-scale glacial lineations (MSGLs) on the bed of the Late Wisconsin Green Bay Lobe in Wisconsin, USA, which exhibited surge-like behaviour during deglaciation. Previous work has shown that streamlined bedforms are the product of erosional streamlining of pre-existing sediment. Analysis of bedform height and elongation ratio using curvature-based relief separation (CBRS) and K-means clustering of 32,003 bedforms reveals a continuum of six morphotypes ranging from drumlins, through "channeled" more elongated multi-crested drumlins, to MSGLs. Further statistical analysis shows that morphotypes cluster into six types of streamlined surfaces (S1-S6) recording progressive elimination of an antecedent overridden topography to produce a smoother bed. Initial, relatively high-relief drumlinized surfaces (S1, S2) occur around the slowerflowing lateral flanks of the lobe, where a pre-existing hummocky morainal topography was only partially modified by subglacial erosion. More streamlined surfaces (S3, S4) dominated by multi-crested more elongate drumlins of reduced relief amplitude are transitional to flow sets of MSGL-dominated surfaces (S5, S6) indicative of much faster-flowing ice streaming along the lobe's axis. Estimates of basal drag based on roughness calculations for each surface type identify a 61% reduction in frictional retardation from poorly streamlined surfaces S1 and S2 to MSGL-dominated surfaces S5 and S6, with a step-like reduction between drumlins and channeled drumlins (S3, S4) possibly recording the rapid onset of fast flow. Subglacial streamlining is argued to be accomplished by a thin (<1 m) "third layer" of deforming subglacial debris between ice and its bed which functioned as an erodent layer. A thin (<3 m) till cap, formed by aggradation of deforming debris, rests unconformably on heterogeneous core sediments. Streamlined subglacial surfaces are comparable to the "functional" surfaces resulting from erosion by a "third layer" of wear debris in engineering tribological systems, and also by gouge on faults. Pleistocene ice sheets expanded over pre-existing landsystems, pointing to the broader relevance of the methodology and findings reported here.

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Section: Discussion: Ice Sheet Beds As Glaciotribological Systemsmentioning

confidence: 99%

LiDAR‐based semi‐automated mapping of drumlins and mega‐scale glacial lineations of the Green Bay Lobe, Wisconsin, USA: Ice sheet beds as glaciotribological systems

Eyles

Bukhari

Sookhan

et al. 2022

Earth Surf Processes Landf

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“…The aeroplanes of Boeing and Airbus were coated with a riblet membrane to realize energy consumption savings of approximately 3% [21,22]. Over the last few decades, the effectiveness of riblets in drag reduction has been demonstrated in many experiments [23][24][25]. However, the spacing (s) and height (h) of the riblet are kept constant to avoid the difficulty of fabrication [26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Controllable deformation based self‐adaptive drag reduction for complex surface

Chen

Cui

Chen

2023

Biosurface and Biotribology

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Reduction of energy consumption and improvement of cruising speed are greatly necessary for underwater vehicles. Previously, regular riblets have been machined and the drag reduction has been verified; however, the riblet parameters are not adjusted like the denticles of sharkskin, which adapt quickly to the complex changing fluid flow. To achieve an improved drag reduction effect on the complicated shape surface, a simple, low‐cost, and timesaving stretching approach was proposed to adjust the riblet parameters on the underwater vehicle surface by controllable deformation. Nature latex rubber membrane with regular micro‐riblets was prepared as a stretching flexible film, and the spacing and height of the micro‐riblets were adjusted by adaptive control of the stretching ratio. The circulating water channel experiment verified the effectiveness and feasibility of the self‐adaptive drag reduction by the controllable deformation method. The results demonstrated that the drag reduction rate of the controllable deformation bionic fish skin was 4.26% compared with a smooth surface at 0.25 m/s with an angle of attack of 0°, which is better than any other angle. The controllable deformation bionic fish skin provides a feasible method for the drag reduction of complex surface adaptive underwater vehicles.

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Interactive experimental study on microgroove structure and drag‐reducing additives in rotating disk apparatus

Chang,

Huang,

Huang

et al. 2024

Asia-Pacific J Chem Eng

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A series of interactive experiments are conducted to analyze the drag reduction technology with a rotating disk apparatus that combines microgroove structure and drag‐reducing additives including polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and sodium salicylate (NaSal). By varying the disk type, concentration of drag‐reducing additives, temperature, and Reynolds number (Re), the corresponding drag reduction rates are obtained effectively. The experimental results indicate that adding CTAC strengthens the heat degradation and shear resistance of PEO; while PEO can enhance the ability of CTAC to form micellar structures and balance energy distribution at low concentrations. Moreover, the synergistic effect of these two additives presents a better drag reduction performance with a maximum drag reduction rate of 24.1%; while the microgroove structure enhances the effect of active drag reduction. Therefore, the combination of active and passive drag reduction technology broadens the application of energy saving and consumption reduction in hydraulic rotating machinery.

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Drag reduction by various micro-grooves in a rotating disk system

Cited by 5 publications

References 33 publications

LiDAR‐based semi‐automated mapping of drumlins and mega‐scale glacial lineations of the Green Bay Lobe, Wisconsin, USA: Ice sheet beds as glaciotribological systems

LiDAR‐based semi‐automated mapping of drumlins and mega‐scale glacial lineations of the Green Bay Lobe, Wisconsin, USA: Ice sheet beds as glaciotribological systems

Controllable deformation based self‐adaptive drag reduction for complex surface

Interactive experimental study on microgroove structure and drag‐reducing additives in rotating disk apparatus

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