摘要:
Thermal-acoustic section (436) for an aircraft (10) for reducing noise along an acoustic path (22) produced from an acoustic source (16) is provided herein. The thermal-acoustic section (436) comprises a plurality of juxtaposed porous layers (400) forming a thermal-acoustic stack (447) that has a first outermost portion (474), a second outermost portion (476) and a central portion (478). The thermal-acoustic stack has a gradually deecreasing characteristic acoustic impedance from the first outermost portion to the central portion and a gradually increasing characteristic acoustic impedance from the central portion to the second outermost portion, to promote transmission loss of the transmitted portion of the noise through the thermal-acoustic stack.
摘要:
In one embodiment, a device includes at least one transducer configured to vibrate within a first frequency range to generate a signal audible by a wearer of the device. The device includes the first material, which has an acoustic impedance at one or more frequencies within the first frequency range that is substantially similar to an acoustic impedance of the wearer's skin at the one or more frequencies. The device includes a second material that has an acoustic impedance at one or more frequencies within the first frequency range that substantially differs from an acoustic impedance of an environment of the device.
摘要:
Amain body case 9 includes an output opening 43 for outputting sound from a sound source to an opposing space between an upper main wall 33 and a lower main wall 34. The main body case 9 includes a front main wall 41 for preventing entering of a water droplet to the output opening 43 and for guiding the sound to a rear side B, and a rear main wall 35 for reflecting the sound to a front side F. A first space 51 between the front main wall 41 and the rear main wall 35, a second space 52 surrounded by a left surface 41C of the front main wall 41 and the rear main wall 35 and the upper main wall 33 and the lower main wall 34 and a third space 53 surrounded by a right surface 41D the front main wall 41 and the rear main wall 35 and the upper main wall 33 and the lower main wall 34 are communicating with one another along a crosswise direction Y at a rear end part of each of these spaces.
摘要:
An arrayable loudspeaker (11) has at least one high frequency driver (39) mounted to a horn (37) and at least one pair of low frequency drivers (41) configured behind and in a closely spaced relationship to the horn to form low frequency side chambers (71) between the drivers and the horn from which acoustic energy produced by the low frequency drivers can propagate. Low frequency exit channels (77) above and below the horn are coupled to the low frequency side chambers (71). The configuration of the horn and low frequency drivers and the low frequency side chambers and low frequency exit channels is such that acoustical outputs of all drivers radiate coaxially from the loudspeaker with substantially constant wide beamwidth in the non-arraying plane. Signal processing can be added to enhance beamwidth control critical frequency ranges above crossover.
摘要:
Die vorliegende Erfindung betrifft eine Beschallungseinrichtung mit einem Schallgeber, welcher eine Hauptabstrahlrichtung aufweist, und mit einem Horn in Form eines sich von einer Schalleintrittsöffnung aus zu einer Schallaustrittsöffnung trichterförmig erweiternden Hohlkörpers, der zumindest eine erste sich zwischen den Öffnungen erstreckende, eben Seitenfläche aufweist, wobei der Schallgeber an oder nahe der Schalleintrittsöffnung angeordnet ist. Um Grenzflächenreflektionen zumindest zu reduzieren und um eine Beschallungseinrichtung mit einer gut ausgerichteten und wohldefinierten Schallwellenfront mit hohem Schalldruckpegel und einem ausgeglichen Frequenzgang bereitzustellen, wird erfindungsgemäß vorgeschlagen, dass der Schallgeber unmittelbar neben der (ersten) ebenen Seitenfläche oder einer gedachten Verlängerung derselben in der Weise angeordnet ist, dass seine Hauptabstrahlrichtung parallel zu der (ersten) ebenen Seitenfläche von der Schalleintritts- zu der Schallaustrittsöffnung hin verläuft.
摘要:
An acoustic matching member (100) that is incorporated into an ultrasonic transducer for transmitting and receiving ultrasonic waves, includes: at least two layers including a first layer (11) and a second layer (12) that have different acoustic impedance values from each other. The first layer (11) is made of a composite material of a porous member (1) and a filling material (2) supported by void portions of the porous member (1), the second layer (12) is made of the filling material (2) or the porous member (1), and the first layer (11) and the second layer (12) are present in this stated order. A piezoelectric member is disposed on a side of the first layer (11) of the acoustic matching member (100) to form an ultrasonic transducer or an ultrasonic flowmeter. The acoustic matching member (100) does not have independent intermediate layers between the layers, so that delamination hardly occurs and the difficulty in the designing associated with the presence of intermediate layers can be avoided.
摘要:
A probe (100) includes: a piezoelectric layer (111) to generate ultrasonic waves, a backing layer (112) to absorb ultrasonic waves generated at the piezoelectric layer and proceeding toward a rear, a reflective layer (113) occupying an area smaller than an area of the piezoelectric layer and provided in between the piezoelectric layer and the backing layer to amplify the ultrasonic waves generated at the piezoelectric layer, and a lens layer (115) to focus the ultrasonic waves proceeding toward a front of the piezoelectric layer at a certain point.
摘要:
An ultrasound probe comprising a housing, a transducer assembly operable to transmit ultrasonic energy towards a zone of the probe adapted to be acoustically coupled to an object or area of interest, a cooling system comprising a heat transfer device arranged to transfer heat generated by the transducer assembly to one or more regions or areas located outside such transducer assembly. The heat transfer device comprises a graphene-based material.