Abstract: The present concepts include a zero-porosity structure having a plurality of structural elements arranged to provide a negative Poisson's ratio and, further, a new mechanism to generate negative Poisson's ratio is single material, zero-porosity structure.

Abstract: In at least some aspects, an auxetic structure includes a first sheet defining therein a plurality of a plurality of structural elements projecting from the first sheet, the plurality of structural elements being arranged to provide a negative Poisson's ratio, and a second sheet disposed adjacent the first sheet to define a first internal cavity between the first sheet and the second sheet. In yet other aspects, one or more additional sheets may be advantageously provided to provide a multi-layered structure having auxetic properties.

Abstract: In some aspects, an auxetic structure includes a first sheet and a second sheet, the first sheet defining therein a plurality of first openings in a first pattern, the plurality of first openings providing a first porosity and the second sheet defining therein a plurality of second openings in a second pattern to provide a second porosity. The second sheet is positioned to overlay the first sheet so that the plurality of second openings at least partially occlude the plurality of first openings to define a plurality of third openings in a third pattern, the plurality of third openings defining a third porosity less than that of the first porosity or the second porosity. The second sheet is connected to the first sheet by a plurality of distinct connection elements.

Abstract: Auxetic structures, effusion-cooling auxetic sheets, systems and devices with auxetic structures, and methods of using and methods of making auxetic structures are disclosed. An auxetic structure is disclosed which includes an elastically rigid body with opposing top and bottom surfaces. First and second pluralities of elongated apertures extend through the elastically rigid body from the top surface to the bottom surface. The first plurality of elongated apertures extends transversely with respect to the second plurality of elongated apertures. The first and/or second pluralities of elongated apertures are obliquely angled with the top surface of the elastically rigid body. The elongated apertures are cooperatively configured to provide a desired cooling performance while exhibiting stress reduction through negative Poisson's Ratio (NPR) behavior under macroscopic planar loading conditions.

Abstract: In at least some aspects, an auxetic structure includes a first sheet defining therein a plurality of a plurality of structural elements projecting from the first sheet, the plurality of structural elements being arranged to provide a negative Poisson's ratio, and a second sheet disposed adjacent the first sheet to define a first internal cavity between the first sheet and the second sheet. In yet other aspects, one or more additional sheets may be advantageously provided to provide a multi-layered structure having auxetic properties.

Abstract: The present concepts include a zero-porosity structure having a plurality of structural elements arranged to provide a negative Poisson's ratio and, further, a new mechanism to generate negative Poisson's ratio is single material, zero-porosity structure.

Abstract: A material which exhibits auxetic characteristics and control of thermal expansion characteristics while experiencing significant stress reduction is disclosed. The material has a repeating pattern of void structures along both lateral symmetry lines and longitudinal symmetry lines.

Abstract: A material which exhibits auxetic characteristics and control of thermal expansion characteristics while experiencing significant stress reduction is disclosed. The material has a repeating pattern of void structures along both lateral symmetry lines and longitudinal symmetry lines.

Abstract: A system includes a turbine engine having a fuel injector. The fuel injector includes fluid ducts, each having a fuel inlet coupled to a distinct fuel source. The system includes a compressed air source that provides compressed air simultaneously to the fluid ducts, and a convergence point where combined fuel and air streams from the ducts are mixed. The fuel inlets are in a parallel flow arrangement such that no fuel from one fuel injector is present at another fuel injector.

Abstract: One aspect relates to an apparatus having a combustion chamber and a duct in fluid flow communication with the combustion chamber. The apparatus includes at least one opening adapted for delivering a liquid fuel into the duct. The apparatus further includes at least one passage adapted for delivery of a gas upstream of the at least one opening for minimizing the entrance of a fluid other than the gas into the fuel delivery opening.

Abstract: A low head water turbine comprising a runner having a cylindrical outer surface and a plurality of similar blades similarly pivotably secured along their inner sides to the outer surface of the runner so as to pivot in the direction of rotation of the runner between a closed position lying adjacent the outer surface of the runner and an open position at an angle thereto. A housing having end walls and a rounded side wall extending therebetween, completely encases the runner and its blades. The runner is eccentrically mounted to end walls of the housing for rotation about a horizontal axis so that the cylindrical outer surface is spaced closer to an upper portion of the housing side wall and farther from a lower portion. A water inlet opening is located in a lower, forward portion of the housing, below the axis of rotation of the runner. A water outlet opening is located in a lower, rearward portion of the housing.

Abstract: A low head water turbine comprising a runner having a cylindrical outer surface extending between opposite ends and a plurality of similar blades having inner and outer sides extending to ends. The blades are evenly spaced about the surface of the runner and extend to the ends of the runner. The blades are similarly pivotably secured along their inner sides to the outer surface of the runner so as to pivot in the direction of rotation of the runner between closed position lying adjacent the outer surface of the runner and open position at an angle thereto. A housing having end walls and a rounded side wall extending therebetween, completely encases the runner and its blades. End walls of the housing are proximal to the ends of the runner. The runner is eccentrically mounted to the end walls of the housing for rotation about a horizontal axis so that the cylindrical outer surface of the runner is spaced closer to an upper portion of the housing side wall and farther from a lower portion.