Abstract: A method of reducing noise from a combustor of a gas turbine engine includes the steps of establishing a maximum noise limit that may be for a particular frequency range. A primary fuel flow percentage, which may be emitted from a fuel nozzle arrangement having various groupings of simplex and duplex nozzles, is then established. An immersion depth measured between an aft rim of a swirler and a distal tip of the fuel nozzles may then be reduced thereby reducing the noise amplitude.

Abstract: A fire suppression nozzle can include a first fluid channel configured to be in fluid communication with a first fluid having a first flow velocity and a second fluid channel configured to be in fluid communication with a second fluid having a second flow velocity. A mixer can be disposed between the first fluid channel and the second fluid channel such that the mixer is configured to induce streamwise vorticity in at least the first fluid exiting first fluid channel to cause mixing of the first fluid and the second fluid to reduce a flow speed of a mixture of the first fluid and the second fluid.

Abstract: A turbo generator rotor assembly is provided and includes a generator, first and second bearings on a compressor-side and a turbine-side of the generator and a combination seal configuration in which leakage from the compressor cools the first bearing, the generator and the second bearing. The combination seal configuration leads to minimal leakage past the turbine with the generator and the first and second bearings being cooled with leakage flow from the compressor.

Abstract: A compressor has an inlet port and a discharge port. The discharge port communicates into a resonator chamber. The resonator chamber includes a first stage resonator array and a second stage resonator array downstream of the first stage resonator array with a connecting passage intermediate the first and second resonator array. Each of the resonator arrays includes a pair of spaced resonator arrays sub-portions, with each of the sub-portions including a plurality of cells extending into a housing member, and have a bottom wall and an open outer wall communicating with the flow passage, with a plurality of orifices extending into each of the cells. The orifices have a smaller diameter than a hydraulic diameter of the cells.

Abstract: A turbo generator rotor assembly is provided and includes a generator, first and second bearings on a compressor-side and a turbine-side of the generator and a combination seal configuration in which leakage from the compressor cools the first bearing, the generator and the second bearing. The combination seal configuration leads to minimal leakage past the turbine with the generator and the first and second bearings being cooled with leakage flow from the compressor.

Abstract: A nozzle assembly for a fire suppression system includes a body having an inlet end for receiving a flow of fire extinguishing agent from the fire suppression system at an inlet pressure and a nozzle portion extending from the body. The nozzle portion includes an interior cavity having an outlet end, a center body arranged within the interior cavity adjacent the outlet end, and a plurality of exit orifices formed in an outer wall of the nozzle portion, in communication with the interior cavity, for vectoring the flow of fire extinguishing agent exiting therefrom and to reduce a noise level of the nozzle assembly. At least one perforated filter member is positioned upstream from the plurality of exit orifices formed in the nozzle portion, for reducing the inlet pressure of the flow of fire extinguishing agent.

Abstract: A turbo generator rotor assembly is provided and includes a generator, first and second bearings on a compressor-side and a turbine-side of the generator and a combination seal configuration in which leakage from the compressor cools the first bearing, the generator and the second bearing. The combination seal configuration leads to minimal leakage past the turbine with the generator and the first and second bearings being cooled with leakage flow from the compressor.

Abstract: A fire suppression nozzle can include a first fluid channel configured to be in fluid communication with a first fluid having a first flow velocity and a second fluid channel configured to be in fluid communication with a second fluid having a second flow velocity. A mixer can be disposed between the first fluid channel and the second fluid channel such that the mixer is configured to induce streamwise vorticity in at least the first fluid exiting first fluid channel to cause mixing of the first fluid and the second fluid to reduce a flow speed of a mixture of the first fluid and the second fluid.

Abstract: A nozzle assembly for a fire suppression system is disclosed, which includes a body having an inlet end for receiving a flow of fire extinguishing agent from the fire suppression system at an inlet pressure, a nozzle portion extending from the body and having an interior cavity defining a central axis, wherein a plurality of exit orifices are formed in an outer wall of the nozzle portion, in communication with the interior cavity, for vectoring the flow of fire extinguishing agent exiting therefrom and to reduce a noise level of the nozzle assembly, and at least one perforated filter member positioned upstream from the exit orifices in the nozzle portion, for reducing the inlet pressure of the fire extinguishing agent in furtherance of noise level reduction.

Abstract: A fire suppression nozzle can include a first fluid channel configured to be in fluid communication with a first fluid having a first flow velocity and a second fluid channel configured to be in fluid communication with a second fluid having a second flow velocity. A mixer can be disposed between the first fluid channel and the second fluid channel such that the mixer is configured to induce streamwise vorticity in at least the first fluid exiting first fluid channel to cause mixing of the first fluid and the second fluid to reduce a flow speed of a mixture of the first fluid and the second fluid.

Abstract: A compressor has an inlet port and a discharge port. The discharge port communicates into a resonator chamber. The resonator chamber includes a first stage resonator array and a second stage resonator array downstream of the first stage resonator array with a connecting passage intermediate the first and second resonator array. Each of the resonator arrays includes a pair of spaced resonator arrays sub-portions, with each of the sub-portions including a plurality of cells extending into a housing member, and have a bottom wall and an open outer wall communicating with the flow passage, with a plurality of orifices extending into each of the cells. The orifices have a smaller diameter than a hydraulic diameter of the cells.

Abstract: A compressor has a housing assembly having a plurality of ports including a suction port and a discharge A male rotor is mounted for rotation about an axis. A female rotor is enmeshed with the male rotor and mounted in the housing for rotation about an axis for drawing a flow from the suction port, compressing the flow, and discharging the compressed flow through the discharge port. A cavity group is between the discharge port and the male rotor and female rotor. The cavity group has a first member separating a plurality of cells and a foraminate cover member atop the first member.

Abstract: A fire suppression nozzle can include a first fluid channel configured to be in fluid communication with a first fluid having a first flow velocity and a second fluid channel configured to be in fluid communication with a second fluid having a second flow velocity. A mixer can be disposed between the first fluid channel and the second fluid channel such that the mixer is configured to induce streamwise vorticity in at least the first fluid exiting first fluid channel to cause mixing of the first fluid and the second fluid to reduce a flow speed of a mixture of the first fluid and the second fluid.

Abstract: A compressor (20; 600) comprising: a housing assembly (22) having a plurality of ports including a suction port (24) and a discharge port (26); a male rotor (30) mounted for rotation about an axis (500); a female rotor (32) enmeshed with the male rotor and mounted in the housing for rotation about an axis (502) for drawing a flow from the suction port, compressing the flow, and discharging the compressed flow through the discharge port; a cavity (120, 122; 620, 622, 624, 626) group (116, 118; 612, 614, 616, 618) between the discharge port and the male rotor and female rotor, the cavity group comprising: a first member (124, 80; 682, 680, 630, 632) separating a plurality of cells; a foraminate cover (130, 132; 640, 642, 644, 646) member atop the first member.

Abstract: An improved induced draft gas burner assembly for low NOx residential and light commercial gas furnaces is disclosed. The improved burner includes an upstream assembly coupled to a fuel inlet and an air inlet. The air inlet is coupled to a neck extending between the air inlet and the outlet of the neck, both of which may be disposed within an optional chamber. If used, such a chamber also includes an outlet coupled to a burner. In practice, the chamber and neck behave as a Helmholtz resonator that can be tuned to provide an upstream impedance Zup that exceeds the downstream impedance Zdown of the components downstream of the burner assembly.

Abstract: A sound attenuating heat exchanger for an internal combustion engine includes a housing, a barrier wall and a fin. The housing includes an exhaust inlet, an exhaust outlet, a coolant inlet and a coolant outlet. The exhaust inlet is connected to the exhaust outlet by an exhaust flow passage. The coolant inlet is connected to the coolant outlet by a coolant flow passage. The barrier wall fluidly separates the exhaust flow passage from the coolant flow passage. The fin extends from the barrier wall into the exhaust flow passage, and includes a resonator adapted to attenuate sound waves traveling through exhaust gas within the exhaust flow passage. The barrier wall and the fins are adapted to exchange heat energy between the exhaust gas flowing through the exhaust flow passage and coolant flowing through the coolant flow passage.

Abstract: A sound attenuating heat exchanger for an internal combustion engine includes a housing, a barrier wall and a fin. The housing includes an exhaust inlet, an exhaust outlet, a coolant inlet and a coolant outlet. The exhaust inlet is connected to the exhaust outlet by an exhaust flow passage. The coolant inlet is connected to the coolant outlet by a coolant flow passage. The barrier wall fluidly separates the exhaust flow passage from the coolant flow passage. The fin extends from the barrier wall into the exhaust flow passage, and includes a resonator adapted to attenuate sound waves traveling through exhaust gas within the exhaust flow passage. The barrier wall and the fins are adapted to exchange heat energy between the exhaust gas flowing through the exhaust flow passage and coolant flowing through the coolant flow passage.

Abstract: An improved induced draft gas burner assembly (31, 131, 231, 331, 431, 531, 631) for low NOx residential and light commercial gas furnaces (10, 10a) is disclosed. The improved burner includes an upstream assembly coupled to a fuel inlet (55) and an air inlet (43). The air inlet (43) is coupled to a neck (41, 141, 241, 341, 441, 541, 641) extending between the air inlet (43) and the outlet of the neck (41, 141, 241, 341, 441, 541, 641), both of which may be disposed within an optional chamber (42, 142, 242, 342, 442). If used, such a chamber (42, 142, 242, 342, 442) also includes an outlet coupled to a burner (46, 146, 246, 346, 546, 646). In practice, the chamber (42, 142, 242, 342, 442) and neck (41, 141, 241, 341, 441, 541, 641) behave as a Helmholtz resonator that can be tuned to provide an upstream impedance Zup that exceeds the downstream impedance Zdown of the components downstream of the burner assembly (31, 131, 231, 331, 431, 531, 631).

Abstract: A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system reduces the total drag on a dual, counter-rotating, coaxial rotor system. Other aerodynamic structures may be mounted to the shaft fairing, hub fairings and airframe to facilitate flow around the upper and lower hub fairings to reduce flow separation and drag.

Abstract: A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system is sized and configured to reduce the overall drag on a dual, counter-rotating, coaxial rotor system. Preferably, the rotor hub fairing is fully integrated. The shaft fairing preferably includes a minimal thickness at the midsection to reduce drag with an increasing thickness adjacent the upper and lower hub fairings to reduce the flow separation on the hub fairing surfaces without overly excessive drag. Other aerodynamic structures, such as a horizontal splitter and/or a plurality of turning vanes may be mounted to the shaft fairing to facilitate flow around the upper and lower hub fairings to reduce flow separation and drag.