Abstract: A latticework assembly is provided. The latticework assembly includes a plurality of base laths and plurality of cross laths. Each base lath of the plurality of base laths is spaced apart from each other. The plurality of cross laths extend transverse on the plurality of base laths. Each cross lath of the plurality of cross laths includes a floor that separates opposing sidewalls extending therefrom. Each cross lath of the plurality of cross laths includes a cover. The cover includes opposing sidewalls depending from an underside of the cover; each of the opposing sidewalls of the each cross lath of the plurality of cross laths includes; wherein each of the opposing sidewalls of the cover include an outwardly directed hook. An inwardly directed hook that is engageable with the cover; and the outwardly directed hooks from the cover engage the inwardly directed hooks of the cross lath.

Abstract: A valve is provided for controlling a flow of a fluid between a first environment and a second environment. The valve includes a frame adapted to fit within a perimeter of an aperture in a divider separating the first environment from the second environment. The valve additionally includes a first gate movable within the frame to control a flow of the fluid through the aperture between the first environment and the second environment. The first gate includes a substantially aerodynamically clean surface substantially free from protrusions disrupting the flow of the fluid over the first gate surface. Additionally, the first gate includes a trailing edge having a baffle adapted to cover an aft edge of the frame when the first gate is positioned to have a small opening angle. The baffle includes a plurality of 3-D notches in a front side of the baffle.

Abstract: A valve is provided for controlling a flow of a fluid between a first environment and a second environment. The valve includes a frame adapted to fit within a perimeter of an aperture in a divider separating the first environment from the second environment. The valve additionally includes a first gate movable within the frame to control a flow of the fluid through the aperture between the first environment and the second environment. The first gate includes a substantially aerodynamically clean surface substantially free from protrusions disrupting the flow of the fluid over the first gate surface. Additionally, the first gate includes a trailing edge having a baffle adapted to cover an aft edge of the frame when the first gate is positioned to have a small opening angle. The baffle includes a plurality of 3-D notches in a front side of the baffle.

Abstract: A valve for controlling a flow of a fluid between a first environment to a second environment. The valve includes a frame adapted to fit within a perimeter of an aperture in a divider separating the first environment from the second environment. The valve additionally includes a first gate movable within the frame to control a flow of the fluid through the aperture between the first environment and the second environment. The first gate has a substantially aerodynamically clean surface that is substantially free from protrusions that may disrupt the flow of the fluid over the first gate surface. The aerodynamically clean surface reduces coherent vortex shedding of the fluid as the fluid flows across the surface of the first gate. To further reduce vortex shedding, the first gate includes a rounded leading edge. Additionally, the first gate includes a trailing edge adapted to reduce edge tones.

Abstract: A valve for controlling a flow of a fluid between a first environment to a second environment is provided. The valve includes a frame that fits within an aperture in a divider separating the first environment from the second environment. Additionally, the valve includes at least one gate mounted and movable within the frame to control a flow of the fluid between the first environment and the second environment through the aperture. The gate includes a surface, wherein at least one portion of the surface includes a rough texture. The rough texture reduces coherent vortex shedding of the fluid as the fluid passes over the gate surface.

Abstract: A flow control device and method for eliminating flow-induced cavity resonance within a closed or nearly closed end flow passage (20) having an inlet opening (30) defined between an upstream inlet edge (32) and a downstream inlet edge (34). The passage accepts exterior fluid flow (38) therein via the opening (30). The flow control device includes a stationary inlet guide vane (44) having a leading edge (46), a trailing edge (48), and a number of support members (50) to connect the vane to the inlet. The vane (44) is positioned such that the vane leading edge intercepts the exterior fluid flow shear layer, and the vane trailing edge extends into the passage at the inlet. In a preferred embodiment, the inlet guide vane is located approximately midway between the upstream and downstream inlet edges. The inlet guide vane is cross-sectionally shaped as a cambered airfoil.

Abstract: A flush-dish microphone system for measuring aircraft flyover noise is disclosed. The system includes an acoustically hard base supporting a microphone. The base is configured along its periphery to define a plurality of outwardly extending tapered members. Each of the tapered members includes a pair of converging edges that are each at least in part curved. The curved edges produce a favorable progressive match of acoustic impedance at the ground/tapered member boundary that reduces edge diffraction contamination of the noise signal being measured by the microphone.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.