.... Along with this, drag-reducing riblets hamper the cross-flow near the wall, thus further decreasing the turbulence intensity. Results suggest that turbulent kinetic energy (TKE) has a similar trend to the drag reduction characteristic near the wall. The finding ascertains the potential application...

... the periodic drag and lift forces. 06 12 2020 24 05 2021 09 07 2021 wake characterization vortex shedding drag reduction square body triangular body Flow around bodies of engineering importance is a long-established topic of interest because the flowing fluid can generate...

...H. Asadzadeh; A. Moosavi; A. Etemadi We study drag reduction of a uniform flow over a flat surface due to a series of rectangular microgrooves created on the surface. The results reveal that making grooves on the surface usually leads to the generation of secondary vortices inside the grooves...

..., there exists an optimal groove spacing, which results in the largest drag reduction. The largest drag reduction results from the use of trapezoidal grooves and the smallest results from the use of triangular grooves for the range of parameters considered in this work. Placing the same grooves on both walls...

... the pure statistical properties without consideration of dynamic properties. It can be inferred that the effect of polymer additives has no influence on the intermittency factor. This is consistent with Virk's observation [ 19 ] that “the onset of drag reduction occurs at the same wall shear stress which...

... and we had 28.2% drag reduction from that of smooth cylinder. Also, the flow on the smooth cylinder separated at around 82 deg but the flow separation on a grooved cylinder appeared beyond 90 deg, that reducing the drag. bluff body circular cylinder blade groove drag reduction energy saving...

... [1] McCormick , M. E. , and Bhattacharyya , R. , 1973 , “ Drag Reduction of a Submersible Hull by Electrolysis ,” Nav. Eng. J. , 85 , pp. 11 – 16 . 10.1111/j.1559-3584.1973.tb04788.x [2] Madavan , N. K. , Deutsch , S. , and Merkle , C. L. , 1984 , “ Reduction...

.... tandem cylinders drag coefficient drag reduction wake interaction laminar wake approximation papermaking The flow around two or a cluster of cylinders with different orientations is of interest to different fields of engineering, such as the wind flow around the chimneys of a power plant...

...Ahmed H. Kamel; Subhash N. Shah Manuscript received June 17, 2011; final manuscript received October 12, 2012; published online February 22, 2013. Editor: Malcolm J. Andrews. Fig. 13 Modified drag reduction envelope of SB fluids in coiled tubing (1) Surfactant-based...

... 08 2012 bluff bodies Cartesian grid method drag reduction flow interference immersed boundary method rounded corner square cylinder vortex shedding Instantaneous spanwise vorticity for flow past two square cylinders with corner radius of R=D/4 for different gap ratios at Re...

...Bahram Khalighi; Kuo-Huey Chen; G. Iaccarino The unsteady flow around a simplified road vehicle model with and without drag reduction devices is investigated. The simulations are carried out using the unsteady RANS in conjunction with the v 2 -f turbulence model. The corresponding experiments...

... with the modification of the flow field on the cylinder surface. The decreases in the pressure coefficients on the upwind-facing faces and on the leeward-facing faces lead to drag reduction of the controlled cylinder by ∼25% when compared with the uncontrolled cylinder. 29 10 2010 21 04 2011 02 06 2011...

...% of the propulsion power. 27 10 2009 18 12 2010 17 02 2011 17 02 2011 cavitation drag reduction fluid oscillations friction ships A vertical section of the hull. An initial buttock includes an initial approach to S c . In the process of iterative design, a part...

..., or serrations that have previously been used to reduce airfoil drag will also be considered. 06 06 2010 19 12 2010 04 02 2011 04 02 2011 aerodynamics aerospace components automotive components blades drag reduction fans Industrial fans are widely used for cooling...

... was applied on the new add-on devices. The results from the optimized design were shown to have a 50.9% reduction in drag coefficient. 29 07 2009 06 04 2010 26 08 2010 26 08 2010 agricultural machinery computational fluid dynamics drag reduction fuel Navier-Stokes equations...

... with increasing air flux rate up to an optimum, but the drag rise for greater rates. A synergy of friction reduction under attached ventilated cavity and microbubble drag reduction downstream of it was shown. 31 03 2009 19 03 2010 13 05 2010 13 05 2010 The qualitative difference...

... Fanning friction factor and drag reduction (DR) are defined in the following equations: 1 C f = τ w / ( 1 / 2 ρ U b 2 ) 2 DR = ( C f , W − C f , S ) / C f , W × 100 % The profiles of the friction factor and DR for 25 ppm, 40 ppm...

...Kelly A. Stephani; David B. Goldstein Viscous drag reduction on a submerged surface can be obtained both in the limit of an unbroken gas film coating the solid and in the nanobubble or perhaps microbubble coating regime when an air layer is created with superhydrophobic coatings. We examine...

...Mitsuo Kurata; Yoshiaki Ueda; Teruhiko Kida; Manabu Iguchi The flow past a rectangular cylinder with small cut-corners at the front-edge is investigated to discuss a relation between drag reduction and the cutout dimension. The rectangular shape is selected in eleven kinds of the length-to-breadth...

... increases the damping factor B in van Driest’s model; subsequently reducing the mixing-length, this interprets that the polymer hampers the transfer of turbulent momentum flux, the velocity is increased, and flow drag is reduced. This study also discusses the onset Reynolds number for drag reduction...