... Abstract There is a need for fuel-efficient vehicles to reduce greenhouse emission and minimize the range problem of electric vehicles. Aerodynamic drag reduction provides one of the cheapest but effective alternatives. Therefore, the development and analysis of new passive strategies that can...

... as a passive drag reduction method for flow over a cylinder that features both attached and separated flow. The impact of the microfiber coating on drag is experimentally investigated at a Reynolds number of 6.1 × 10 4 based on the cylinder diameter. Microfiber coatings of various lengths between 1.1% and 8.0...

... is addressed in this research. Furthermore, the textures disrupt the thermal boundary layer, which can boost thermal transport through recirculation mixing. However, the stagnant fluid trapped within the grooves has weak convective heat transfer. So far, the results have been promising and a drag reduction...

... shown formation of microbubble clusters intermittently, which has Coulomb potential due to negative electric charge on bubble interfaces. microbubble turbulent boundary layer drag reduction multiphase flow flow visualization VISUALIZATION OF MICROBUBBLE DISTRIBUTION INSIDE TURBULENT...

... Abstract Practical implementation of ship drag reduction techniques can lead to substantial fuel savings and lessening environmental impacts of maritime transportation. One of such technologies is based on injecting air underneath ship hulls, which results in the formation of thin air cavities...

... Abstract It has been widely expected that the pulsating control can reduce friction drag in various fluid systems. In order to maximize its effect, a prediction tool of drag reduction using pulsating control is required. The present study aims at the prediction of the drag reduction rate...

... Abstract Drag reduction effect by traveling wavy wall deformation control in turbulent pipe flow was experimentally investigated. From the visualization, we confirmed the downstream traveling wave although it was not uniform in the circumferential direction. When the frequency is 110 Hz...

... pressure and velocity field are measured. In the result of aerodynamic force measurement, driving plasma actuator successfully achieves 3% drag reduction at the most. Flow field measurement of total pressure and two-component velocity shows the difference of vortex structure near the rear end between off...

... 1 Copyright © 2012 by ASME EXPERIMENTAL STUDY ON DRAG-REDUCTION EFFECT OF A NEW SINUSOIDAL RIBLET Monami Sasamori Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology Koganei, Tokyo, Japan Kaoru Iwamoto* Department of Mechanical Systems Engineering, Tokyo...

... coefficient can be decreased by 2%, the aerodynamic cooling drag coefficient by more than 50% and the lift coefficient by 5%. Finally, new designs of aerodynamic drag reduction, based on the combined effects of the different investigated parameters, are proposed. Aerodynamic Drag reduction Simplified...

...turbulent boundary layer, which is a typical external Proceedings of FEDSM2007 5th Joint ASME/JSME Fluids Engineering Conference July 30-August 2, 2007 San Diego, California USA the mean velocity scaled by the friction velocity in- creases with increasing the amount of drag reduction...

... 26 03 2009 Turbulent drag reduction realized by hydrogen microbubbles was investigated experimentally. A method of generating microbubbles of 10–60μm diameter by water electrolysis was established. Experiments were performed using a water circulating tunnel. Microbubbles generated...

... 26 03 2009 This paper is a progress report of a research project toward practical use of air bubble injection as a drag reduction device for ships. Air bubbles injected into the turbulent boundary layer in water flow are well known to have significant skin friction reduction effect...

...Proceedings of FEDSM2007 5th Joint ASME/JSME Fluids Engineering Conference July 30-August 2, 2007 San Diego, California USA tion and for several pipes (4m long) with different diameters. In the case of high concentration conditions (500 and 750ppm), the range of drag reduction without heat exchange...

... pressure and velocity is high only for the streamwise component of the velocity vector for single phase flow (no microbubbles in the flow). A practical application of these measurements is obtaining data and information to better describe the mechanism responsible for the microbubble drag reduction...

... of compliant coatings has been known as the drag reduction means of the skin-friction and was studied by many researchers for 50 years. However the mechanism of drag reduction is not clarified. In this study, experimental study was conducted using compliant walls made of silicone gel to investigate...

... veloc on the other h control of nea the detector i countered by virtual wall is attempted to obtain turbulent drag reduction by locally deforming the wall in a channel flow based on control strategies [1,4] previously Proceedings of ASME FEDSM’02 ASME 2002 Fluids Engineering Divisio Summer Meeting...

... 04 03 2009 This paper discusses experimental results aimed at defining a base drag reduction device based on splitter plates. The unsteady 3D nature of the flow is studied by Schlieren photographies, particle image velocimetry and measurement of the total unsteady lift and drag loads...

... 04 03 2009 The investigation results of the supercavitation for high speed motion of prolate axisymmetric bodies in water are presented. The cavitation drag forming and drag reduction problems are considered on base studying of the peculiarities of the supercavitation flows...

... near the wall, and that the characteristics of vortex structures and bursts were not only dependent on drag-reduction level but also on concentration of additive. Based on the quantified parameters characterizing turbulent events in a wall-bounded turbulent flow, a model of turbulent contribution...