The gas turbine engine includes a fluid system fluidly connecting at least two components of the gas turbine engine, and a tunable resonator in fluid flow communication with the fluid system. The tunable resonator has a resonating volume that varies as a function of a volume of an inflatable member located inside the tunable resonator. The inflatable member having a means for varying the volume of the inflatable member, to thereby tune the resonating volume to a selected frequency of pressure fluctuations or acoustic waves within the fluid system.

A muffler includes an exhaust pipe, a shell, and a cover. The exhaust pipe includes communication holes and is configured to allow an exhaust gas to flow through an interior of the exhaust pipe. The shell is disposed outside the communication holes to cover the communication holes. The cover has a tubular shape. The cover is disposed between the exhaust pipe and the shell. The cover is disposed at a distance, which is specified in advance, from the exhaust pipe.

A tunable insert assembly for a tunable exhaust system is disclosed for use with an air intake engine of a vehicle. The tunable exhaust system may include an intake tube having first and second ends with a first flange, an exhaust tube having third and fourth ends with a second flange, and a clamp to securely affix the first flange of intake tube to the second flange of exhaust tube. The tunable insert assembly may comprise a register ring, insert, and orifice plate with an opening. The insert may be perpendicularly disposed through the opening of orifice plate, while the register ring may be disposed over and circumferentially surrounds an outermost surface of orifice plate. Lastly, the exhaust system may be configured to produce a desired range of tunable sound pressure levels and a desired tunable sound frequency range based on various predetermined diameters and lengths related to the insert(s).

A sound attenuating engine exhaust system and methods are provided for directing exhaust gases away from an internal combustion engine of a vehicle and attenuating undesirable exhaust sounds during engine operation. The sound attenuating engine exhaust system comprises an exhaust inlet configured to receive exhaust gases from the internal combustion engine. A first resonator coupled with the exhaust inlet is configured to dampen at least one frequency of exhaust sound waves by way of destructive wave interference. The first resonator includes an exhaust outlet for directing the exhaust gases out of the first resonator. A second resonator is coupled with the first resonator and configured to dampen one or more frequencies of exhaust sound waves by way of a combination of destructive wave interference and Helmholtz resonance. Hangers facilitate attaching the sound attenuating engine exhaust system to an undercarriage of the vehicle.

An exhaust line for a vehicle includes a muffler extending in an axial direction and having a circumferential wall, and a particulate filter arranged upstream of the muffler. The muffler has a chamber having a lateral inlet in the circumferential wall and at least one pipe having a microperforated portion extending in the axial direction and having a sound damping effect. The microperforated portion is arranged in the chamber, and the pipe extends out of the chamber. The muffler is configured such that exhaust gas flows via the lateral inlet radially through the microperforated portion into the pipe and via the pipe out of the muffler. Furthermore, a vehicle having such an exhaust line is provided.

An exhaust muffler has an outer cylinder into which an exhaust gas from an engine is introduced and a muffling member made of a foamed ceramic material. The outer cylinder has an inner cylinder through which the exhaust gas passes, a part of the muffling member is supported by an outer wall of the inner cylinder via a holding member. The inner cylinder includes, in an area where the inner cylinder overlaps with the muffling member with respect to axial direction of the inner cylinder, a porous wall portion formed with communication holes communicating an inside and an outside of the inner cylinder. The holding member is arranged at a position where it does not overlap with a part of the porous wall portion, so that muffling effect is enhanced, and the muffling member having a low resistance to impact forces can be supported stably by the inner cylinder.

A muffler comprising a hollow cavity enclosed by a first bottom surface, a second bottom surface and a side wall, the side wall connects the first bottom surface with the second bottom surface, an air inlet at one end of the hollow cavity and an air outlet at the other end of the hollow cavity; the cavity is divided into a plurality of chambers in an axial direction, the chambers comprise a first chamber adjacent to the first bottom surface, a second chamber adjacent to the second bottom surface and an intermediate chamber located between the first chamber and the second chamber, the air inlet is in gas communication with the intermediate chamber, and the air outlet is in gas communication with the first chamber.

A lightweight and compact muffler device that can be installed in a limited space in an inside of a generator. A top cover and an undercover (end cover) provided on a top and a bottom of a vertically disposed casing are each formed in substantially trapezoidal shape. Thereby, an inner capacity of the casing can be secured to be large, as a result of which, a size of the muffler device can be made compact, and no extra component is required, so that reduction in manufacturing cost and reduction in weight can be achieved. Since the casing is disposed vertically, it is possible to install the casing even when an installation space is small in an inside of a housing of a generator, and it is possible to make the generator compact.

A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

A sound attenuator has an inner pipe (12) with expansion sections (121) of enlarged diameter corresponding to the constriction sections (141) of an outer pipe (14). The expansion sections (121) in pairs axially delimit an intermediate inner pipe section (122) containing a wall opening (18) and having a reduced diameter relative to the expansion sections (121). The inner surface of the outer pipe (14) in each of its constriction sections (141) is connected to the outer surface of the inner pipe (12) in its respective corresponding expansion section (121). A method of manufacturing such a sound attenuator (10) also is provided and uses internal high-pressure forming.