Turbulent drag reduction by surface manipulations
Dr. Ricardo Garcia-Mayoral
Department of Engineering, Cambridge
Much of the energy consumed by vehicles moving through air and water, as well as to move petrol and other fluids through pipelines, is spent on overcoming the drag generated by near-wall turbulence. It has long been known that certain non-conventional surfaces can reduce this drag, but the physical mechanisms involved are in many cases not well understood, and it is difficult to design surfaces with optimal performance. This talk will discuss those mechanisms for three different technologies: riblets -directional roughness, porous coatings with preferential streamwise permeability, and superhydrophobic surfaces.