A variety of skin-friction drag reduction (FDR) methods for turbulent boundary layer (TBL) flows are reviewed. Both passive and active methods of drag reduction are discussed, along with a review of the fundamental processes responsible for friction drag and FDR. Polymer/riblet combination for hydrodynamic skin friction ... Reducing this drag component would have the obvious advantages of increased speed and/or efficiency. One approach to skin friction drag reduction involves the use of long chain polymer molecules, which can reduce up to 80% of the skin friction under ideal circumstances. Friction of Human Skin against Different Fabrics for Medical Use
The surface skin-friction reduction downstream of one to four successive flush slots injecting at an angle of 10 deg into a turbulent Mach 6 boundary layer has been determined from direct measurements of surface shear. Increasing the number of succeeding slots increases the skin-friction reduction, but this trend reverses at high injection rates.
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Reducing Friction. There are several ways to reduce friction: The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
LAMINAR AND TURBULENT BOUNDARY LAYER ... - Acumen distribution of the mean skin friction coefficient (Cf) on the wall for different ..... Drag reduction inspired by nature has special interest in the field of fluid .... local uniform blowing was imposed in a cross flow through a thin slot. ...... Bandyopadhyay, P. R. & Ahmed, A. Turbulent boundary layers subjected to multiple curvatures.
The Seeker is primarily searching for existing technologies or research studies, outside of the aircraft industry, that provide surface friction reduction in fluid mediums and have potential to be translated to the aircraft industry for skin friction reduction. Other sources of aircraft drag reduction are sought as well.
How to Reduce Friction between Surfaces Reducing Friction. There are several ways to reduce friction: The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings. Skin friction reduction by slot injection at mach 0.8 in ...
Howard, F. G., Hefner, J. N. and Srokowski, A. J., 1975, 6(b). The red region is slightly farther from the wall compared "Multiple slot skin friction reduction", Journal of Aircraft, Vol.
Skin friction reduction by slot injection at mach 0.8 ... Additional Physical Format: Online version: Zakkay, Victor. Skin friction reduction by slot injection at mach 0.8. Washington : U.S. National Aeronautics and Space ... An experimental investigation of turbulent slot injection ... (2013) Hypersonic Turbulent Boundary-Layer Fuel Injection and Combustion: Skin-Friction Reduction Mechanisms. ... Swept-Slot Film-Cooling Effectiveness in Hypersonic Turbulent Flow. ... Investigation of multiple slot film cooling to a blunt nose cone. 6th Fluid and PlasmaDynamics Conference. Citation ... STREAMWISE PORTHOLE FUEL INJECTION FOR BOUNDARY-LAYER ...
In that study, the flow characteristics and flow distribution patterns of a single slot jet as well as a multiple slot jet located at the upper wall of a two-dimensional channel were analyzed numerically. The pressure distribution of the channel and the variation in skin friction coefficients along the impingement surface plate were also presented. How to Reduce Friction between Surfaces Reducing Friction. There are several ways to reduce friction: The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example. Replace sliding friction with rolling element friction, … Skin friction reduction in supersonic flow by injection through slots…