Abstract: A mobile fracking system and methods may include a gas turbine housed at least partially inside a trailer and an exhaust attenuation system configured to receive exhaust gas from the gas turbine. The exhaust attenuation system may include a lower elongated plenum configured to receive exhaust gas from the gas turbine and an upper noise attenuation system that is movably connected relative to a distal end of the lower elongated plenum.

Abstract: A mobile fracking system and methods may include a gas turbine housed at least partially inside a trailer and an exhaust attenuation system configured to receive exhaust gas from the gas turbine. The exhaust attenuation system may include a lower elongated plenum configured to receive exhaust gas from the gas turbine and an upper noise attenuation system that is movably connected relative to a distal end of the lower elongated plenum.

Abstract: An exhaust baffle apparatus includes an enclosure having longitudinal, lateral, and anterior dimensions. The apparatus defines an internal volume defining an airflow path proceeding from an intake opening to an exhaust opening. There are a multiplicity of mixers within the enclosure. Each mixer includes a length spanning the lateral dimension of the enclosure. Each mixer further comprises a hollow airfoil substantially open at lateral ends of the mixer and at least one vent oriented toward the exhaust opening. A different feature involves a method of dampening noise and heat form engine exhaust.

Abstract: A silencer for a gas turbine includes a first duct portion; a second duct portion connected to the first duct portion, the first and second duct portions forming an elbow region at the connection; and a plurality of elbow shaped vanes provided in the elbow region. The plurality of elbow shaped vanes have equal lengths and are spaced equally apart.

Abstract: A jet engine noise suppression system uses a plurality of microjets that are located on a frame downstream of the exhaust port of a jet engine. Each microjet issues a microjet flow, either liquid or gas, directed at the main jet flow issued by the engine. The mass of the combined microjet flow is substantially smaller than the mass of the jet engine flow. The angle of at which each microjet issues its flow may be variable. The microjets may be located on a pop-up head of a blast deflector or on a upstanding rack.

Abstract: Disclosed is a noise insulation device for aircraft, comprising a first opening that is delimited by a series of conducting surfaces whose inner edge is oriented towards the interior of the noise insulation device from a horizontal cross-sectional perspective and whose outer surface is directed towards the side, a roof, and a second opening which is located opposite the first opening and is delimited by walls. The inventive noise insulation device is characterized in that the size of the second opening can be modified by making changes to the walls.

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 device for simulating sound produced by certain equipment, for example a rotor-stator arrangement of a turbomachine, or for generation of opposing sound fields for active sound control, including active sound reduction and active sound amplification, comprises flow obstacles (2) provided in a flow duct (1) flown by a fluid at which vortices (5, 6) are shed at a certain frequency depending on the shape and size of the flow obstacles and the velocity of flow. The quantity and spatial arrangement of the flow obstacles is selected such that a periodically spatially and temporally changing pressure field for the excitation of a sound field (8) of a certain modal content is produced by the entirety of the vortices shed. This sound field reacts synchronizingly on the vortex shedding. The resonant circuit so formed, whose vortex shedding frequency is in the range of the resonant frequency of the sound field to be excited, is the sound source.

Abstract: Repairs and overhaul procedures are scheduled and implemented with a surprisingly low frequency. Repair and overhaul procedures are implemented wherein conventional noise suppression exhaust sound attenuation systems receive structural and functional enhancements for promoting longevity of efficient system operations. Degradation deficiencies of conventional configurations of sound attenuation systems for exhaust augmenters and deflector panels are avoided or prevented so that insulation re-packing rates may be minimized. Apparatus and associated methodology establish and implement maintenance protocols for installing specially-designed kits in existing sound attenuation systems.

Abstract: A gas turbine exhaust passage is realized which may suppress the radiation of strong ultra low frequency noise to the outside without amplifying the turbulence of an high speed exhaust gas flow rate or a pressure pulsation generated in a gas turbine. At least a portion of a wall of a gas turbine exhaust passage (3, 5) is formed of an acoustically transmissive material (36, 56) for allowing a low frequency noise of several tens of Hz or less to pass therethrough sufficiently. Also, the acoustically transmissive material is made of one or more of a porous material, a porous heat insulating material, a mesh having a large flow resistance, cloth or film material. Further, the acoustically transmissive material is supported by a porous plate or a frame. In a case where an acoustically transmissive material is used only for an exhaust chimney (5), the exhaust chimney (5) is supported by a rack (11). Further, a soundproof panel (12) may be attached to the rack (11).

Abstract: A sound attenuating device including a sound insulating structure and a windband. The sound insulating structure is constructed and arranged to receive vented air from an exhaust vent. The windband is affixed to the sound insulating structure and is constructed and arranged to prevent water from entering the sound insulating structure. The windband also provides a structure for attenuating sound.

Abstract: Methods and apparatus for suppressing cell howl with negligible impact on engine test conditions are described. The apparatus, in an exemplary embodiment includes a flow distorter configured to be positioned close to a nozzle exit of an engine nozzle, and a flow distorter support for maintaining the flow distorter at a selected location. The flow distorter is adjustably secured to the support so that a distance at which a tip of the distorter is located relative to support is adjustable.

Abstract: Enchancements to the side walls of a ground runup (jet aircraft engine testing) facility, the enhancements comprising horizontal vents in the side walls, rolled or semicylindrical tops of the side walls and sloped front ends to the side walls, the combination of the enhancements providing stable air flow to engines even in unstable air conditions.

Abstract: An element, pillow or cushion for the reduction or elimination of noise in buildings, from highways, from industrial machinery, and from airports comprising a sound transparent covering and a sound absorbent interior, the element or pillow being used singly or in properly spaced arrays.

Abstract: An improved silencer panel construction for use in the exhaust gas stream of power generation equipment is described. The silencer panel has an outer periphery of U-shaped channel. Perforated webbing is attached within the outer periphery to strengthen the outer periphery and reduce thermal gradients building up within the web during operation. Acoustical insulation is provided within the silencer panel and held in place by screening as well as perforated cladding. A plurality of silencer panels are spaced apart within the silencer chamber to attenuate the noise produced by the exhaust gas stream.

Abstract: A method and apparatus for reducing noise originating in a flowing stream of gases in which the noise is progressively absorbed from the flowing stream to provide noise of reduced intensity relative to noise intensity at the upstream end of the stream, and the noise of reduced intensity actively attenuated with controlled sound energy. To facilitate the active attenuation of noise, the flowing stream is preferably divided into a plurality of smaller streams after a level of reduced intensities is attained and the active attenuation performed independently in each of the smaller streams. The apparatus is in the nature of a conduit (10) which defines a single duct extending from the inlet end (14) for a portion of the length of the conduit. Downstream, the single duct joins with a plurality of ducts (32,34) extending to the outlet end (16). An active noise attenuating device is preferably provided in each of the plurality of ducts.

Abstract: Apparatus for reducing the pressure and thermal impingement effects of a supersonic exhaust gas plume emanating from a rocket motor nozzle. A pair of wedge-shaped pieces comprise a disrupter positioned on opposite sides of the central longitudinal axis of the rocket exhaust plume in order to disrupt and disperse the plume concentration. The positioning of these pieces is such that at least a portion of the exhaust gas plume may pass between them. The disrupter defines a flow area normal to the central axis of the exhaust flow which is less than the cross sectional area of the exhaust plume at the position of the disrupter pieces. The reduced flow area causes the exhaust flow to undergo a normal shock wave adjacent the position of the disrupter device before the exhaust gases pass between the disrupter body pieces at subsonic velocity.

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).

Abstract: A jet blast deflector fence designed to present a cleaner, simpler, aesthetically pleasing appearance, the deflector fence comprised of simple frames which include only two structural members, a curved rib channel member securedly and hingedly attached to an airport apron and a vertical King post of angle iron which is rigidly secured at its lower end and hingedly attached at its upper end to the channel. A corrugated deflection surface overlies and is fastened to the curved rib members. Because of the respective hinged attachments of the rib members to the apron and the King posts to the rib members the distance between the lower end of the channel member and the King post can be adjusted to reduce the apron space required for the fence. One or more ventilating slots are included to reduce turbulence in order to improve deflection performance.

Abstract: The invention provides a device for collecting the exhaust gas jet of an aircraft reactor with orientable propulsion nozzle or with a gas jet orientable with respect to the longitudinal axis of said reactor, during ground testing of the latter, as well as a testing installation for aircraft reactors equipped with said device. The device comprises an external cylindrical jacket bell-mouthed at its end intended to be situated opposite the tested reactor and a cylindrical internal jacket, concentric to said external jacket and intended for straightening out the exhaust gas jet when this latter or the propulsion nozzle of the tested reactor has a slant with respect to the axis of said reactor.

Abstract: A protective facility for suppressing jet aircraft noise which has a primarily horseshoe shape for surrounding a jet aircraft. Within the horseshoe and situated to the rear of any plane within the facility is found a metal, mesh lattice which redirects exhaust gasses from the jet aircraft engines upwards. Noise from the engines, in the form of sound waves, passes through the lattice and impinges upon the facility walls; being absorbed by these walls which are covered with a sound absorbing material. At the entrance to the facility are leaves hinged to the top legs of the horseshoe which roll on curved rails. These leaves may thus be swung inwards to substantially completely enclose a plane which has been placed within the horseshoe shaped facility. The leaves are also covered with sound absorbing material to absorb and deaden noises produced at the jet engine intakes. The facility walls, including the gates, are substantially rectangular in cross-section.

Abstract: A jet pump comprises a nozzle (1) for a high speed primary flow, a mixing tube (2) into which the primary flow is directed by the nozzle (1), and an inlet (3) to the mixing tube (2) for a secondary flow, the inlet (3) surrounding the primary flow nozzle (1). Means (2') is provided for changing the cross section of the mixing tube (2) abruptly in order to produce a rise in static pressure immediately downstream, thereby increasing mixing of the primary and secondary flows, stabilizing the mixing process and enabling significant noise reduction when used in engine testing apparatus.

Abstract: Disclosed is an exhaust silencer for high-power gas turbines having an outer case made from steel plate formed into a Greek fret pattern, and proved with inner soundproofing panels of which are covered with standardized, insulating-soundproofing compound bricks. Each compound brick is preferably of square shape and include a front brick and a rear brick. The front brick is made from an annealed stainless steel plate, beveled at its corners, perforated in its central area only, and bent along each of its edges to form a bracket shape in cross section, inside which bracket-edged perforated steel plate is inserted a pad of insulating material of standardized dimensions, to act as an insulator-soundproofer made from very-high-quality materials subject for high temperature use.

Abstract: A compact turbine engine exhaust gas noise suppressor has a housing having a first chamber, a second chamber having an outlet and communicating with the first chamber through a transfer passage, and a third chamber communicating with the first chamber through a perforated dividing wall and having a resonant sound attenuator positioned therein. A sound absorbing member is positioned in the second chamber to create therein a serpentine flow path extending between the transfer passage and the outlet. The exhaust gas noise is attenuated by flowing the exhaust gas into the first chamber through a duct into which ambient cooling air is educted, and then forcing the exhaust gas outwardly through the serpentine flow path.

Abstract: An apparatus for reducing the pressure and thermal impingement effects of a supersonic exhaust gas plume emanating from a rocket motor nozzle. A disrupter body positioned within the exhaust plume along the central longitudinal axis thereof disrupts and disperses the plume concentration. The body has a central passage through which a portion of the exhaust may pass. The body and passage are sized and shaped to provide a flow area normal to the exhaust flow less than the cross-sectional area of the exhaust plume at the position of the body. The reduced flow area causes the exhaust flow to undergo a normal shock wave upstream of the body before passing through and around the body at a subsonic velocity. The presence and configuration of the body disrupts and disperses the plume concentration, and the reduced flow velocity significantly reduces the downstream pressure and thermal effects of the exhaust gas plume.

Abstract: Exhaust gas duct for gas turbines, including an axial discharge housing, a deflection piece connected downstream of the axial discharge housing in exhaust gas flow direction, the deflection piece having a substantially horizontal first diffusor section and a substantially vertical second diffusor section, the first and second diffusor sections each having a respective inclined edge facing each other, a grid disposed in the deflection piece for redirecting exhaust gas flow into the vertical direction, a substantially vertical exhaust gas chimney disposed downstream of the deflection piece in exhaust gas flow direction, and a noise suppressor disposed in the deflection piece.

Abstract: An inflatable seal for sealing the open area between the perimeter of an opening in a wall of a building and the body of a vehicle received in the opening. The seal comprises an inflatable member which is mounted on the wall in the opening and a blower assembly for inflating the inflatable member and for maintaining it in an inflated or expanded disposition wherein it extends inwardly into the opening for sealingly engaging the sides of the vehicle body. The seal further comprises an inner partition in the inflatable member for reducing outward bulging of the walls thereof to thereby maintain the inflatable member in substantially inwardly extending relation in the opening and recoil members are provided for retracting the inflatable member to a position wherein it is adjacent the perimeter of the opening when the blower assembly is deenergized.

Abstract: A blast deflecting fence having separate upper and lower deflecting surfaces which overlap. The lower deflecting surface is curved so that a jet blast directed towards it is deflected upwards. The upper deflecting surface is positioned so that lower portion of the upper surface overlaps the upper portion of the lower surface and is horizontally separated therefrom. The upper deflecting surface is inclined between 30.degree. below the vertical and vertical so that jet blasts are directed upwards. End walls are provided perpendicular to the blast fence to constrain the lengthwise flow of exhaust gases.

Abstract: A device for shielding the sound energy radiated from the jet engines of an aircraft formed from two panels being in horizontal and vertical longitudinal view arranged concavely in a clamshell type.

Abstract: A ring of tubes extends inwardly from a noise suppressor housing wall sufficiently far to impinge upon the periphery of the high velocity core of a supersonic jet exhaust to disrupt the core and reduce the sound power generated. A large volume of outside cooling air is induced by jet pump action into the suppressor; and a portion of this cooling air is ducted through the tubes and into the exhaust stream to maintain the temperature of the tubes below an acceptable level to prevent their premature destruction.

Abstract: A gas turbine engine exhaust duct of combination circular and rectangular configuration, and accompanying muffler which provides cooling and silencing of exhaust flow from the gas turbine engine. The arrangement utilizes minimum space without sacrifice of performance.

Abstract: A stationary jet exhaust noise suppressor has an elongate housing contain a longitudinal tunnel. The hot exhaust from a jet engine blows through the tunnel and is deflected upwards at the tunnel's end. A number of resonant chambers are located along the tunnel's length and have resonant frequencies corresponding to objectional frequencies in the jet exhaust noise spectrum. Since there are a number of perforations in the walls of the tunnel, the resonant chambers are put in communication with the jet exhaust noise in the tunnel to attenuate the objectionable frequencies. Since the resonant chambers are formed by rigid stainless steel panels, trouble free, long term noise suppression is assured. A cooling duct is provided in the walls of the housing to draw in ambient air to reduce the possibility of heat damage.