F15DFLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS nozzles, spray heads B05B; devices to decrease friction or resistance or to increase speed of ships B63B; ship rudders B63H25/38; influencing the flow or the viscosity of fluids with chemical additives C09K3/00, C10M; hydraulic engineering E02B; fluid circuit elements F15C; one-way check valves F16K15/00This subclass comprises boundary-layer control and other arrangements and methods, not provided for in other classes, for influencing the flow of fluids relative to constraining surfaces and after leaving these surfaces, e.g. producing or removing turbulence, deflecting jets, guiding flow through bends in conduits, affecting distribution of fluid in a conduit, reducing fluid friction.In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme. F15D1/00 F15D1/00Influencing flow of fluids F15D1/0005Baffle plates F15D1/001Flow of fluid from conduits such as pipes, sleeves, tubes, with equal distribution of fluid flow over the evacuation surface F15D1/0015Whirl chambers F15D1/002by influencing the boundary layer F15D1/06 and F15D1/12 take precedence F15D1/0025using passive means, i.e. without external energy supply F15D1/003comprising surface features, e.g. indentations or protrusions F15D1/0055, F15D1/006 take precedence F15D1/0035in the form of riblets F15D1/004oriented essentially parallel to the direction of flow F15D1/0045oriented essentially perpendicular to the direction of flow F15D1/005in the form of dimples F15D1/0055comprising apertures in the surface, through which fluid is withdrawn from or injected into the flow F15D1/006comprising moving surfaces, wherein the surface, or at least a portion thereof is moved or deformed by the fluid flow F15D1/0065using active means, e.g. supplying external energy or injecting fluid F15D1/007comprising surfaces being moved by external supplied energy F15D1/0075comprising electromagnetic or electrostatic means for influencing the state of the fluid, e.g. for ionising the fluid or for generating a plasma F15D1/008comprising fluid injection or suction means F15D1/0085Methods of making characteristic surfaces for influencing the boundary layer F15D1/009by means of vortex rings F15D1/0095by means of injecting jet pulses of fluid wherein the injected fluid is taken from the fluid and re-injected again, e.g. synthetic jet actuators F15D1/008 takes precedence F15D1/02in pipes or conduits F15D1/025by means of orifice or throttle elements F15D1/04Arrangements of guide vanes in pipe elbows or duct bendsConstruction of pipe conduit elements or elbows with respect to flow, specially for reducing losses in flow F15D1/06by influencing the boundary layer use of materials, e.g. to reduce surface friction C09K3/00 F15D1/065Whereby an element is dispersed in a pipe over the whole length or whereby several elements are regularly distributed in a pipe F15D1/08of jets leaving an orifice nozzles or outlets with means for mechanically breaking up or deflecting the jet B05B, e.g. B05B1/26 F15D1/10around bodies of solid material F15D1/12by influencing the boundary layer use of materials, e.g. to reduce surface friction C09K3/00 F15D1/14Diverting flow into alternative channels in hydraulic engineering E02B