Investigation of the drag reducing effect of hydrophobized sand on cylinders

Abstract

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Drag Prediction in the Near Wake of a Circular Cylinder based on DPIV Data

“…The formula of this estimation method is given below and referenced in various recent studies, e.g., comparison of fluid forces of an airfoil (Zhou et al 2011), drag calculations of a flat plate at various angles of attack (Sharma and Deshpande 2012), drag estimations of circular cylinder with synthetic jet (Feng and Wang 2012), symmetric vortex shedding in the wake of a cylinder (Konstantinidis and Balabani 2007), drag reduction of square cylinders with cut-corners (He et al 2014), characterization of the effect of flowcontrol excitation from synthetic jet actuators on airfoil drag (Goodfellow et al 2012) and drag reduction of hydrophobized sand on cylinders (Brennan et al 2014). …”

Flexible conformable hydrophobized surfaces for turbulent flow drag reduction

“…This is to replicate the conditions they face in the water circulating flow chamber where drag coefficient measurements were taken. The same flow process was undertaken as has been previously published by Brennan et al 24 . Results from the contact angle measurements and confocal microscope are shown in Table 2 .…”

“…Much of this work has focussed on either cylinders or on flat surfaces. This work has been performed in two main ways: theoretically using computational fluid dynamics (CFD) simulations 5 6 7 8 9 10 11 12 13 14 and experimentally with the aid of towing tanks and circulation experiments 15 16 17 18 19 20 21 22 23 24 . When an object travels through a fluid, for example a ship traveling through water, or a fluid travels through an object, for example water through a pipe, drag forces are experienced.…”

From Extremely Water-Repellent Coatings to Passive Icing Protection—Principles, Limitations and Innovative Application Aspects

“…(see Figure 2), known in the scientific literature as superhydrophobic, superomniphobic or supernonwetting depending on the liquids involved [6][7][8][9][10], opens a broad range of potential practical relevance. It includes, but is not limited to self-cleaning surfaces [11][12][13], passive icephobic [14][15][16] and anti-bioadhesive coatings [17][18][19], systems for removal of oil contamination from water basins [20][21][22][23], anti-corrosive coatings [24][25][26], drag-reducing surfaces [27][28][29][30], pervaporation membranes [31,32], green engineering [33] or piezoresonance chemical and biological sensors [34][35][36][37][38]. [18,37,38].…”