On the scaling of air layer drag reduction

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August undefined, 2024

Web1 de fev. de 2013 · Measurements confirmed that air layer drag reduction (ALDR) is sensitive to upstream disturbances, but a clean boundary layer separation line (i.e. the … Webreduction (BDR), has been shown to produce local drag reduction in excess of 80% in laboratory-scale experiments, and has therefore attracted the interest of numerous …

Bionics and green technology in maritime shipping: an assessment …

Web8 de nov. de 2024 · The air layer drag reduction (ALDR) of an axisymmetric body in oscillatory motions is investigated in this paper with open source toolbox OpenFOAM. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations are used to determine the viscous flow and the volume of fluid (VOF) model is adopted to capture the interface of … Web9 de mar. de 2024 · To investigate the stream-wise distribution of skin-friction drag reduction on a flat plate with bubble injection, both experiments and simulations of bubble drag reduction (BDR) have been conducted in this paper. Drag reductions at various flow speeds and air injection rates have been tested in cavitation tunnel experiments. … ip industripartner ab

Bubble-induced skin-friction drag reduction and the abrupt …

Web16 de mar. de 2024 · Cavitating flow near free surface is a complicated issue and may provide new inspiration on high-speed surface cruising. This study observes stable supercavitating flow as a new phenomenon in a launch experiment of axisymmetric projectile when the upper side of the projectile coincides with the free surface. Web10 de abr. de 2024 · Superhydrophobic surfaces could repel water due to the capillary force associated with surface roughness, which has a large range of applications, such as underwater drag reduction, heat transfer enhancement, oil/water separation, and so on. However, the engineering applications of superhydrophobic surfaces rely on the stability … Web22 de nov. de 2010 · Several large scale experiments have been conducted at the US Navy's Large Cavitation Channel on a 12.9 m long flat plate model investigating bubble … ip india.gov.in

Superhydrophobic surfaces to reduce form drag in turbulent …

Web15 de jan. de 2024 · The drag reduction rate in this study reached 20%. The results demonstrate that a continuous air film on superhydrophobic surfaces plays an important … Web22 de mar. de 2024 · In this paper, the air lubrication method is applied to high-speed SWATH (small waterplane area twin hull) to reduce the resistance. The influence of air injection locations on drag reduction is investigated. The computed results are compared with experimental results, and the grid independence test is performed. Then, the … ip indihome gamingWeb3 de jan. de 2024 · uneven micro/nanostructures of lotus leaves. The superhydrophobicity and drag reduction ratios at low velocities are highly improved using a laser ablation method on metal substrates. However, unstable air layers trapped on superhydrophobic surfaces are usually cut away by a high-velocity ﬂow, which greatly reduces the drag … ip info grabber

"WebWhen implemented at relatively low or high gas fluxes, this air-injection method is termed bubble drag reduction (BDR) and air layer drag reduction (ALDR), respectively. While the majority of studies to date … " - On the scaling of air layer drag reduction

On the scaling of air layer drag reduction

Active and Passive Turbulent Boundary-Layer Drag Reduction

Web13 de abr. de 2024 · J.Busch , W Barthlott, M.Brede, W.Terlau, M. Mail, “ Bionics and green technology in maritime shipping: an assessment of the effect of Salvinia air-layer hull coatings for drag and fuel reduction”, The Royal Society Publising, 9 October 2024. WebDrag Reduction in a Homogeneous Flow. Keizo Watanabe, in Drag Reduction of Complex Mixtures, 2024. Abstract. Drag reduction phenomenon in not only an internal flow but also an external flow is shown experimentally by comparison of that of Newtonian fluids. It is presented that the trend of the drag reduction of a sphere is quite similar to dilute …

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Web7 de abr. de 2024 · Research on the drag reduction of micro-grooved walls has been carried out in pipe flow and channel flow. Early systematic investigations began in the … Web11 de abr. de 2024 · Drag increases in excess of 10% were observed for the highest rain rate tested, which represented an unrealistically-high precipitation condition equivalent to about 250 mm/hr full scale. A non ...

Web1 de jan. de 2010 · Request PDF On Jan 1, 2010, J.K. Choi and others published Numerical Study on the Behavior of Air Layers Used for Drag Reduction Find, read … Web4 de out. de 2024 · The drag reduction occurs via two distinct physical pathways. The first pathway, as studied previously, involves actuating the surface at frequencies comparable …

Web24 de nov. de 2008 · These results indicated that there are three distinct regions associated with drag reduction with air injection: Region 1, BDR; Region 11, transition between …

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Web11 de abr. de 2024 · In this paper, we study the aerodynamic shape of dandelion, derive the scaling law of resistance, determine the Vogel exponent. In particular, we find that the … ip info hsnlWebDirect Numerical Simulation (DNS) of two-phase flow is performed to investigate the air layer drag reduction (ALDR) phenomenon in turbulent flow over a backward-facing step. In their experimental study, Elbing et al. (JFM, 2008) have observed a stable air layer on an entire flat plate if air is injected beyond the critical air-flow rate. In the present study, air … ip informatykaWeb3 de fev. de 2013 · Measurements confirmed that air layer drag reduction (ALDR) is sensitive to upstream disturbances, but a clean boundary layer separation line (i.e. the … ip info infoWeb26 de ago. de 2016 · We study both experimentally and theoretically the descending motion due to gravity of a fluid drop surrounded by another immiscible fluid in a confined … ip info geolocationWeb1 de fev. de 2013 · A scaling of the critical air flux for ALDR was developed from balancing shear-induced lift forces and buoyancy forces on a single bubble within a shear flow. The resulting scaling successfully collapses ALDR results from the current and past studies … ip info freeWebAir-Layer Drag Reduction (ALDR) technique is one of the most effective air lubrication techniques, which creates a complete air layer to separate the hull surface from the water. Drag reduction effect has been proved to be over 80% for a flat plate in previous experiments. However, how to form an air-layer as complete as possible attached to the … oral-b genius x 20100s whiteWebInterference Drag, Air Drag - Nov 25 2024 Lift, ... Assessment of Dual-point Drag Reduction for an Executive-jet Modified Airfoil Section - Mar 06 2024 Physics for Game Developers ... Preliminary Full-scale Power-off Drag of the X-15 Airplane for Mach Numbers from 0.7 to 3.1 - Nov 01 2024 ip info tracker