Abstract: A rotor casing having an inner casing wall surrounding an annular gas path, a plurality of rotor blades radially extending into such annular gas path. The inner casing wall has an annular recess positioned radially outwardly of the gas path outer line and axially downstream of the rotor blades. A plurality of circumferentially spaced-apart vanes are positioned within the annular recess. The vanes may be profiled and circumferentially spaced from one another to accelerate air flowing between circumferentially adjacent vanes. The vanes may include an airflow partition extending between the top edges of at least 2 circumferentially adjacent vanes, from each such vanes' leading edge to each such vanes' trailing edge.

Abstract: A modified inlet region of a turbofan engine for reducing or eliminating turbofan flutter. The modified inlet region is defined by annular inside surface and a fan. The modified inlet region is upstream and co-axial with the fan. A plurality of fins are disposed circumferentially around the annular inside surface and extend radially into the modified inlet region. Each fin may be attached normal to the annular inside surface or at an angle. The plurality of fins serve to disrupt the propagation of acoustic reflections leading to turbofan flutter.

Abstract: A therapeutic apparatus, which treats fatigue of the whole body, is provided. A plurality of speakers/sensors which apply an oscillating pressure to a subject are provided. An airtight chamber and a vacuum pump unit, which change the subject into the state of a negative pressure from the atmospheric pressure, are provided. A control unit adjusts distribution of the oscillating pressure by the output of each speaker/sensor is provided. Further, the control unit adjusts each speaker/sensor, in order that the oscillating pressure of a same extent is applied to a plurality of parts of the body, simultaneously. Thereby, the whole body of the subject can recover from fatigue.

Abstract: A variable frequency Helmholtz resonant cavity includes a Helmholtz resonant cavity body, two Helmholtz resonant cavity pipes with different cross-sectional areas and lengths and a control valve plate. The Helmholtz resonant cavity body is connected with the main pipe of the intake system via the Helmholtz resonant cavity pipes, and the control valve plate is disposed at the location where the two Helmholtz resonant cavity pipes meet.

Abstract: A duct design and methods for designing ducts are described herein. The duct has a profile described by an equation that balances momentum of the fluid flowing through the duct with an adverse pressure gradient. The duct profile is configured to: (i) maintain the fluid's momentum to be greater than the adverse pressure gradient present at any location within the duct, such that no boundary layer separation occurs; and (ii) achieve a fluid exit momentum of approximately zero.

Abstract: A variable frequency Helmholtz resonant cavity includes a Helmholtz resonant cavity body, two Helmholtz resonant cavity pipes with different cross-sectional areas and lengths and a control valve plate. The Helmholtz resonant cavity body is connected with the main pipe of the intake system via the Helmholtz resonant cavity pipes, and the control valve plate is disposed at the location where the two Helmholtz resonant cavity pipes meet.

Abstract: A flexible multiple speaker support apparatus is provided for supporting a plurality of speakers therein and includes a flexible, hollow speaker support unit which includes a plurality of open, sound emission channels. The speakers are housed within the flexible, hollow speaker support unit, and the speakers are placed in registration with the open, sound emission channels. With one embodiment of the invention, the flexible, hollow speaker support unit includes a flexible, tubular speaker support member, and the flexible, tubular speaker support member includes a plurality of the open, sound emission channels. The speakers are placed in registration with the open, sound emission channels. With another embodiment of the invention, a suspension bracket assembly is connected to the flexible, hollow speaker support unit for supporting the flexible, hollow speaker support unit in a desired orientation from a ceiling, wall or other surface.

Abstract: A method, system and computer program product are provided for implementing dynamic noise elimination. A system frame includes a plurality of acoustical sensory devices monitoring the system for problem frequencies. The system frame includes a plurality of tubes. When the tube is open, airflow is allowed. When identified tubes are closed, quarter-wavelength attenuation is provided for a frequency in a range of frequencies, based upon a length of the tube when closed. Each of the plurality of tubes is selectively controlled to be operable open or closed at a particular length, responsive to identified problem frequencies.

Abstract: A loudspeaker module includes a hollow main body, two rotatable connecting portions, and two loudspeakers. The hollow main body includes two opposite sidewalls. Each of the opposite sidewall defines a first opening, an inner sidewall of the first opening defines an annular rotating slot. One end of the connecting portion extends an annular flange shaped corresponding to the rotating slot. The two rotatable connecting portions are respectively rotatably connected to the main body via the flange rotating about the rotating slot. Two loudspeakers are disposed in an end of the corresponding rotatable connecting portion away from the main body.

Abstract: A flexible multiple speaker support apparatus is provided for supporting a plurality of speakers therein and includes a flexible, hollow speaker support unit which includes a plurality of open, sound emission channels. The speakers are housed within the flexible, hollow speaker support unit, and the speakers are placed in registration with the open, sound emission channels. With one embodiment of the invention, the flexible, hollow speaker support unit includes a flexible, tubular speaker support member, and the flexible, tubular speaker support member includes a plurality of the open, sound emission channels. The speakers are placed in registration with the open, sound emission channels. With another embodiment of the invention, a suspension bracket assembly is connected to the flexible, hollow speaker support unit for supporting the flexible, hollow speaker support unit in a desired orientation from a ceiling, wall or other surface.

Abstract: In this device, three chambers, three chips with multiple holes and three membranes senses and magnifies sound signal from miles away to a magnitude that can be heard by device holder. Sound wave enter from the membrane, vibration energy is transmitted by highly compressed air within chamber 3, which then is magnified by multiple small holes in its chip. The same vibration is magnified by compressed air in chamber 2, which then is magnified by multiple small holes in its chip. Then the vibration is magnified by compressed air in chamber 1, which then is magnified by multiple small holes in its chip. Device holder adjust the air density in chamber 1, 2 and 2 by sliding chamber 3 inside chamber 2, and by sliding chamber 2 inside chamber 1. Sound wave is magnification in proportion to air compression ratio between two connected chambers, and magnified by holes on each of the three chips, thereby sound wave received from miles away is tremendously magnified.

Abstract: The invention uses tubes for the reduction of radiated duct noise. The tubes may be used to attenuate narrow band noise by diverting a portion of the acoustic energy through the tubes back into the duct. Upon reintroducing the diverted flow out of phase with the primary flow, acoustic cancellation is achieved. The frequency at which this occurs is dependent on the difference in the path lengths through the tubes and the separation distance—the distance separating the inlet and outlet of the tube. This invention can be used over varying frequency ranges by using an arrangement of flexible, constant length tubes. The effective frequency range is tailored by varying the separation distance and also allows the varying the angular arrangement of the tubes for more effective attenuation of spinning modes having varying propagation angle.

Abstract: The invention uses tubes for the reduction of radiated duct noise. The tubes may be used to attenuate narrow band noise by diverting a portion of the acoustic energy through the tubes back into the duct. Upon reintroducing the diverted flow out of phase with the primary flow, acoustic cancellation is achieved. The frequency at which this occurs is dependent on the difference in the path lengths through the tubes and the separation distance—the distance separating the inlet and outlet of the tube. This invention can be used over varying frequency ranges by using an arrangement of flexible, constant length tubes. The effective frequency range is tailored by varying the separation distance and also allows the varying the angular arrangement of the tubes for more effective attenuation of spinning modes having varying propagation angle.

Abstract: An expansion valve capable of reducing noise due to acoustic resonance by allowing for adjustment of resonance characteristics of piping connected to a restricting portion and filled with a substantially liquid refrigerant, and an air conditioner using the same are provided. The expansion valve has a valve body 1, a restricting portion 18 formed inside the valve body 1, two piping connection portions 11, 12 communicating with the upstream side and the downstream side of the restricting portion 18, and at least one opening 30 that opens a refrigerant flow passage to outside of the valve body 1, the refrigerant flow passage extending from the piping connection portion 12 to which a piping 19 filled with a substantially liquid refrigerant is connected to the restricting portion 18.

Abstract: A satellite speaker system includes a side firing low mid driver mounted in a sub-enclosure which is vented into a second sub-enclosure through an acoustic resistance vent and to a third sub-enclosure through a variable aperture second vent. The vents further serve as pivots to allow the side-firing speaker to be rotated through a predetermined range, simultaneously varying the aperture of the second vent. The pivots are isolated by o-rings to provide an airtight seal to the sub-enclosures, as well as to provide vibration control. Third, fourth and fifth resistively damped vents allow the first and second sub-enclosure to establish acoustic communication with the environment. The front firing driver/s that reproduces the mid and high frequencies are mounted in a fourth sub-enclosure.

Abstract: A loud speaker enclosure being made in two parts with each of the side panels cut into angle form to assist in angle adjustment, alone with pivot hinges and friction lid supports used to hold it's angled position. The enclosure can be modified to accommodate any design or style of drivers boards. In addition to any design of loudspeaker, any orientation of enclosing may be incorporated with this invention. This enclosure can be used without driver board 5B were by Box B would then operate as an angling base for Box T.

Abstract: A mounting assembly for removably supporting a microphone in an operative position and in a manner which will protect the microphone against attenuating high impact phonetic peaks. A plurality of support assemblies are selectively attachable to one another to assume a variety of predetermined individually selectable configurations, wherein each of the predetermined configurations are determinative of a preferred operative orientation of the microphone. The plurality of support assemblies include a microphone support structured, to suspend the microphone in a predetermined orientation; a filter support structured, to adjustably support a filter in a substantially aligned, protective relation to the microphone; and an auxiliary support, structured to be removably and adjustably attached in supporting relation to at least one of said filter or microphone supports.

Abstract: Disclosed is a sub-woofer module which has a simple construction and provides a good low-frequency bass in compliance with an audience's taste. The sub-woofer module has an enclosure, a baffle board which separates the enclosure into first and second chambers, and a speaker coupled to the baffle board. The baffle board is engaged with a screw shaft and moves upward and backward along the screw shaft to vary the volume of the first and second chambers. A reverse-conical cap is disposed above the enclosure to permit the upwardly projected sound to be projected in 360 degrees, and a conical base is disposed below the enclosure to permit the downwardly projected sound to be projected in 360 degrees. The audience can listen to sound of the same quality regardless their position in relation to the sub-woofer module.

Abstract: A loudspeaker apparatus includes an elongated hollow tube having two open ends, which tube may be a rigid or telescoping tube, and has a wide range speaker mounted at each end of the hollow tube. A pair of deflector surfaces may be flat, polymer surfaces mounted to a base and are positioned at an angle facing each speaker at each end of the tube for deflecting the sound waves emanating from each speaker in accordance with the positioning of the tube. The tube may also have a tuned port formed into the side of the tube and connected to an arcuate passageway built into the hollow portion of the inside of the tube for producing a bass resonance from the backwaves of both speakers.

Abstract: Disclosed is an acoustic practice mute for brass musical wind instruments having a bell end which is of simple construction, light weight, acoustically transmits muted or dampened sound to the ears of the player without any electrical or membrane amplification, in which the sound transmitted is not distorted or changed from a natural sound, in which the volume of sound to the player's ears can be regulated, and which can be used by the player as a normal mute.