Abstract: A portable attitude test stand (PATS) for an aircraft engine, has: a support frame mountable on a trailer of a road vehicle; a test cell supported by the support frame and sized to receive the aircraft engine, the test cell operable to rotate the aircraft engine about a pitch axis and a roll axis of the aircraft engine; and an actuator operatively connected to the test cell and to the support frame, the actuator operable to lower and raise the test cell relative to the support frame between a transport configuration in which the test cell has a transport height and a test configuration in which the test cell has a test height, the test height being greater than the transport height.

Abstract: A marine drive is provided. The marine drive includes a propulsion unit, a supporting cradle that couples the propulsion unit to a transom bracket for attachment to a marine vessel, and a cowling system that at least partially covers a portion of the propulsion unit and a portion of the supporting cradle. The cowling system includes upper, middle, and lower cowling components, and the middle and lower cowling components are separated by a dynamic gap. The marine drive further includes a sound blanket positioned between the supporting cradle and the middle and lower cowling components. The sound blanket is configured to span the dynamic gap and block sound that would otherwise emanate from the propulsion unit via the dynamic gap.

Abstract: A baffle for an air intake section of a rotary machine includes a pair of oppositely disposed perforated walls that at least partially define an exterior of the baffle and an interior cavity of the baffle. The baffle also includes a pair of panels disposed within the interior cavity. Each of the panels is coupled proximate a respective one of the perforated walls, such that a chamber is defined between the panels. Each of the panels includes a first sound absorbing material that is substantially completely vaporizable at an operating temperature of the rotary machine.

Abstract: An on-base enclosure for equipment is disclosed. The on-base enclosure has walls attached to a base for equipment such that the walls are attached to the base at a distance away from the base. By providing the walls away from the base, more room is provided around the equipment within the enclosure.

Abstract: The invention provides an enclosure, in particular, an acoustic enclosure, for thermal equipment, for example a gas turbine or a gas turbine auxiliary module. The invention also provides a method of constructing such an enclosure.

Abstract: The invention provides an enclosure, in particular, an acoustic enclosure, for thermal equipment, for example a gas turbine or a gas turbine auxiliary module. The invention also provides a method of constructing such an enclosure.

Abstract: An exhaust system for an electric power generation system is disclosed. The exhaust system may include a muffler configured to suppress noise associated with operation of an engine associated with the electric power generation system. The muffler may be configured to be mounted in a roof of a housing configured to contain at least part of the electric power generation system. The muffler may be configured to form an outside surface of the roof. Removal of the engine from the housing may be facilitated by removal of the muffler from the roof, such that the engine can be lifted out of the housing.

Abstract: A noise attenuation device for testing a jet engine.

Abstract: The gas turbine exhaust sound suppressor, or exhaust silencer, and method are for a gas turbine and reduce low frequency exhaust flow noise while avoiding the creation of additional acoustical standing waves, e.g. from wake shedding at certain predictable frequencies. A plurality of elongated flow obstruction members, e.g. pipes or airfoils, extend within the exhaust passage to reduce acoustic waves within the exhaust flow, and at least some of the elongated flow obstruction members have different widths. Each of the elongated flow obstruction members is positioned at a respective angle within a predetermined angular range transverse to the flow direction, with the predetermined angular range being greater than or equal to 10 degrees from normal to the flow direction.

Abstract: A ground run up enclosure (10) which comprises an air inlet structure (12), a test chamber (14), an acoustic enclosure (16) and a main enclosure door (118). The air inlet structure (12) is adapted to receive ambient air and redirect it into the test chamber (14). The test chamber (14) is designed to receive a portion of an aircraft (20) therein. The acoustic enclosure (16) receives the airflow from the test chamber (14). The airflow continues through the acoustic enclosure (14) until it contacts a front surface of the main enclosure door (118) and is redirected upward and out of the enclosure.

Abstract: There is provided an acoustic structure and a method of manufacturing such acoustic structure. The acoustic structure comprises at least one uncured facesheet ply defining a plurality of perforations, an adhesive that includes a corresponding plurality of perforations, and a honeycomb core portion adhered to the facesheet ply by the adhesive. The acoustic structure undergoes a single curing process, advantageously an autoclave curing process, to cure the entire acoustic structure. By adhering at least one uncured facesheet ply to the honeycomb core portion, the curing process is capable of curing both the facesheet ply and the adhesive with a single curing process. The single curing process accordingly obviates additional process steps and a sacrificial adhesive layer typically used in other acoustic structures.

Abstract: The fine jet control type sound absorption system of this invention, aimed at absorbing low-frequency sound with both discrete frequency and broadband frequency to the same degree as already existing acoustic lining can do, is composed of two parts. One is a barrier wall covering an air space in which the concerning low-frequency sound propagates and having a multiplicity of small holes formed therein. The other is the means for causing a fine jet passing through these small holes into or out from the air space. This sound absorption system realizes a fine jet in the vicinity of the barrier wall for the purpose of canceling the sound inside the air space by means of the interference of the sound with the fine jets. Any of or a combination of shape of small holes, jet ejection angle or suction angle, amount of jet flow, thickness of a barrier wall back layer and air flow angle at which secondary air flows into the barrier wall back layer is selected.

Abstract: A method is disclosed for testing a jet aircraft engine at a time when an actual wind direction differs from a prevailing wind direction. The method is conducted in a ground runup enclosure (GRE), typically comprising a rear wall, a pair of side walls attached to the rear walls and an open front side opposite the rear wall, the front side facing in a prevailing wind direction. The method comprises moving the aircraft into the GRE, aligning the aircraft so that the air inlet of its engine faces the actual wind direction, and running the engine up to full power to test its condition. The method of the present invention permits the GRE to be used under a variety of unfavourable wind conditions, thereby improving its usability.

Abstract: A sound generating or emitting machine having a component comprising a material with a high internal damping and tensile strength, the material comprising (1) a metallic base material, and (2) a metallic second phase with an at least partially martensitic structure. The material may also be an alloy comprising a base material in which additional alloy elements have a very low solubility.

Abstract: A machinery sound absorbing apparatus includes a machine which generates a machinery sound, and a sound absorbing unit provided above the machine to have a convex shape in an upward direction. The sound absorbing unit includes a reflection plane as an underside surface opposing to the machine. The reflection plane is formed of a sound absorbing material and is a set of plane elements, each of which has an angle of 30 degree or less with respect of a vertical direction. Also, the reflection plane is smooth to a wavelength of the machinery sound.

Abstract: An acoustic testing device is relatively small enough and light enough to be transported from business to business and room to room, and yet still has acoustic characteristics sufficient to characterize a test item's noise profile in a relatively short period of time. The device preferably achieves this result by providing inner and outer housings coupled through noise and vibration isolation, the inner housing having at least some mutually non-orthogonal walls, and the sound detection apparatus comprising spatially translating microphones.

Abstract: The present invention relates to a ground test installation for the jet engines (5A, 5B) of an airliner (2) equipped with at least two jet engines linked to the wings of the aircraft, comprising, for each jet engine (5A, 5B), a silencer (8A, 8B) having a body of generally cylindrical elongate shape, said silencers being intended to each be arranged behind the nozzle of one of said jet engines. According to the invention, this installation comprises a casing (6) which is acoustically insulating and permeable to air, intended to envelop at least the front part of the fuselage (3) and the wings (4A, 4B) of the aircraft (2), and the rear wall of which (7A, 7B) is connected to the front end part of each of said silencers (8A, 8B).