A construction system for mechanical metamaterials based on discrete assembly of a finite set of modular, mass-produced parts. A modular construction scheme enables a range of mechanical metamaterial properties to be achieved, including rigid, compliant, auxetic and chiral, all of which are assembled with a consistent process across part types, thereby expanding the functionality and accessibility of this approach. The incremental nature of discrete assembly enables mechanical metamaterials to be produced efficiently and at low cost, beyond the scale of the 3D printer. Additionally, a lattice structure constructed of two or more rigid, compliant, auxetic and chiral part types enable the creation of heterogenous macroscopic metamaterial structures.

A feed-through assembly for a bulkhead for moving and static engine components. The feed-through assembly can be configured to include flexible convolutions that allow for movement and sealing of the engine component relative to the bulkhead. In one aspect, a flexible convoluted spherical element can be provided in the feed-through assembly. In another aspect, a flexible convoluted bellow element can be provided in the feed-through assembly. These flexible convoluted elements can have multiple convolution sections including convolution sections with varying stiffness. The convolution sections can be configured to allow movement of the shaft relative to the bulkhead, including, transverse deflection and tilt.

In a cowl for a nozzle, an internal wall has a cross-section with a determined abscissa on the axis defining a neck line on the internal wall. The cowl has, downstream of the determined abscissa, indentations in the trailing edge which delimit chevrons distributed in the circumferential direction. The internal wall of the cowl diverges radially towards the interior, in a second axial half-plane passing through the tip of a chevron, from the upstream tangent on the point of the neck line in the second axial half-plane, and the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of the determined abscissa of the neck line.

A gas turbine engine component includes a wall that has an inner surface and an outer surface. An inlet is defined by the inner surface. At least one non-rectangular slot is defined by the outer surface and includes at least one protrusion extending into the slot. A slot passage fluidly connects the inlet to the at least one non-rectangular slot. The slot passage comprises an inlet portion that extends through the wall from the inlet to an intermediate portion. An outlet portion extends through the wall from the intermediate portion to the at least one non-rectangular slot.

A turbofan engine comprising an outer bypass duct, an annular bypass flow path between the outer bypass duct and a core engine, an engine component forming an airflow obstruction adjacent the outer bypass duct, an air cooler having a tube, the tube having at least a sinuous portion extending in the annular bypass flow path, the sinuous portion extending along the outer bypass duct, downstream of the airflow obstruction, the sinuous portion configured for exchanging heat between a fluid circulating in the tube and air circulating in the bypass flow path during operation of the turbofan engine.

A laser chamber of a discharge-excitation-type gas laser apparatus may include a container which contains laser gas therein; a pair of discharge electrodes arranged in the container; a cross flow fan configured to supply the laser gas to a discharge space between the discharge electrodes, the cross flow fan including a rotation shaft with which the cross flow fan rotates in a predetermined rotation direction and a plurality of blades, each longitudinal direction of which is parallel to an axial direction of the rotation shaft; and a stabilizer arranged outside a rotation trajectory of the cross flow fan, and arranged such that a difference between a maximum position and a minimum position of an end portion in the rotation direction on a side opposite to the rotation direction is larger than 0 and is smaller than an interval of two blades adjacent to each other among the plurality of blades.

An airfoil includes an airfoil wall that defines a leading end, a trailing end, and first and second sides joining the leading end and the trailing end. First and second ribs each connect the first and second sides of the airfoil wall. Each of the first and second ribs define a tube portion that circumscribes a rib passage and includes cooling apertures, and first and second connector arms that solely join the tube portion to, respectively, the first and second sides of the airfoil wall. The airfoil wall and the first and second ribs bound a cooling channel there between. The cooling apertures of the first and second ribs open at the cooling channel such that there is a cooling circuit in which the rib passages of the first and second ribs are fluidly connected through the cooling apertures and the cooling channel.

A ducted fan is provided including a fan casing surrounding a plurality of fan blades mounted to a rotating drive shaft. The plurality of blades define a tip stagger angle of greater than 68 degrees and the fan casing defines an annular recess defined by an inner wall of the fan casing, the annular recess extending about the circumferential direction proximate a blade tip of each of the plurality of blades. The annular recess may define an average recess depth greater than 10 percent of the tip chord length. The annular recess may also define a length ratio equal to a recess length over the tip axial chord length that is greater than 1.5.

An airfoil vane includes an airfoil section including an outer wall that defines an internal cavity; and a baffle situated in the internal cavity, the baffle including a baffle wall that defines a central cavity having a leading end and a trailing end corresponding to a leading end and a trailing end of the airfoil section, and a tail extending from the baffle wall, the tail including at least one feature configured to disturb an airflow surrounding the tail. A baffle for the airfoil vane assembly and a method of assembling a ceramic matrix composite airfoil vane are also disclosed.

A vibrational dampening element is attached to a component and configured to adjust the amplitude of oscillations of the component. The vibrational dampening element includes a mass. The mass includes a main body and a member extending from the main body. A casing that encapsulates the mass. A fluidic chamber defined between the mass and the casing. A first fluidic portion is disposed between a first side of the mass and the casing. The first fluidic portion includes a first accumulator portion directly neighboring the member. A second fluidic portion is disposed between a second side of the mass and the casing. The second fluidic portion includes a second accumulator portion directly neighboring the member. The first accumulator portion is in fluid communication with the second accumulator portion. The vibrational dampening element further includes a primary passage that extends between the first fluidic portion and the second fluidic portion.