72results about How to "Reduce engine noise" patented technology

An assembly useful in reducing aircraft engine noise such as turbofan engine noise comprises: (a) a core portion comprising at least one entrance end and at least one exit end for the passage of acoustic energy therethrough; (b) a first member having an exterior face and an interior face, wherein the first member is adjacent to at least a part of the core portion, and the first member has a plurality of openings therein to permit the passage of acoustic energy therethrough; and (c) a second member having an exterior face and an interior face, wherein the interior face of the second member is adjacent to the core portion. The core portion may be a honeycomb acoustic structure, and the first member may be perforated to permit the passage of acoustic energy into and out of the conduit portion.

Waveguide or flow guide surfaces can improve the efficiency of fluid flow through tubes or over surfaces. When incorporated in a tube, the waveguides improve flow and function as sound absorbers making them useful in engine mufflers, firearm silencer/suppressors and jet engine exhaust attenuators. On surfaces, the waveguides can reduce fluid drag and find use on projectiles (e.g., bullets), airfoils for aircraft, and land borne vehicles. The waveguide array in either a tubular chamber or on a surface comprises a plurality of successive wave-like undulations inclined generally in the direction of flow and when employed in tubes extending inwardly to permit an unobstructed path for the fluid gas from entry to exit. The waves define annular wave cavities between their successive inwardly extending edges and the wall of the chamber with each cavity having a cavity mouth open to the unobstructed path. The waveguides are sized and spaced so that gas vortices are created within the cavities when gas flow occurs which vortices create a fluid boundary layer that assists the gas flow.

A detonation engine which creates thrust by generating a detonation wave, wherein the overall engine structure is simplified, and continuous output can be obtained, comprises: a rotational flow generation device which generates rotational flow about an axis in a mixed gas of air and fuel or of oxygen and fuel; a detonation chamber arranged downstream from the rotational flow generation device, formed in a ring-shape radially extended and continuous in the circumferential direction, which continuously combusts in the circumferential direction the mixed gas in which the rotational flow is generated to generate detonation waves, and draws it in from the radial inside and exhausts it to the radial outside; and a nozzle which is connected to the detonation chamber, and jets the high temperature and pressure combustion gas generated by the detonation waves flowing from the detonation chamber, to the rear while expanding it, and converts it into thrust.

In various aspects of the invention a flow vortex suppression apparatus for use in an air intake duct having a mass air flow sensor is disclosed. The flow vortex suppression apparatus includes an air flow permeable fibrous vortex dispersive media installed into the air duct in a position upstream of the mass flow sensor and configured to occlude the air duct such that air flow in the duct is constrained to pass through the vortex dispersive media. The vortex dispersive media is configured and adapted to diffuse vortices and reduce air turbulence of an air stream entering the mass flow sensor, thereby reducing variations and noise in a flow measurement signal from the mass air flow sensor.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

A snowmobile has a four-stroke engine mounted in an engine cradle and an exhaust system connected to the engine. The exhaust system includes a generally U-shaped exhaust pipe extending forwardly from the engine to a first point disposed forwardly of the engine cradle, and of suspension assemblies of the skis, and extending rearwardly from the first point to a second point disposed rearwardly of a front of the engine cradle.

A jet engine exhaust nozzle flow effector is a chevron formed with a radius of curvature with surfaces of the flow effector being defined and opposing one another. At least one shape memory alloy (SMA) member is embedded in the chevron closer to one of the chevron's opposing surfaces and substantially spanning from at least a portion of the chevron's root to the chevron's tip.

A waste heat recovery system is provided for an internal combustion engine having a piston, a cylinder and an intake manifold, significantly improving gas mileage efficiency without reliance on alternative fuels. The system includes a heat loop having a heat transfer fluid, a compressor in fluid communication with the intake manifold to supply compressed air thereto, a Stirling engine operated and optimized via thermal communication with the heat loop, and operatively coupled to the compressor. The system includes a chiller in thermal communication with the heat loop, and with the intake manifold to cool the compressed air communicate to the cylinder. The system may include additional Stirling engines operating other devices, or being operated by a device, such as a propeller. A vehicle can incorporate the system and route fluid to and from a radiator. The system can be used in both portable and stationary applications.

A fan blade for the fan of a gas turbine engine has a radially outer tip portion which, in use, is adjacent to a fan case of the engine. The tip portion includes a movable sealing element for sealing a gap between the tip portion and the fan case. The sealing element movably adapts to changes in the spacing of the gap to maintain a seal between the tip portion and the fan case.

A throttle plate assembly with a wedge for limiting air flow upon initial acceleration.

An apparatus for reducing engine noise includes a side cover configured to operatively connect to a side of an engine block. The side cover has a first layer configured to be adjacent to an outer surface of the side of the engine block. The first layer is made of a first acoustic-absorbing material. The side cover also has a second layer configured to be adjacent to the first layer opposite the engine block. The second layer is a second substantially rigid material establishing an acoustic barrier and is configured to operatively support at least one engine component such as an electrical or fluid line, such as by an integrally formed fastener or channel.

There are provided a front side frame having a closed cross section extending in a vehicle longitudinal direction and including a mount-bracket attachment part for attaching a PT mount bracket provided at a PT mount for supporting a powertrain and a crash can attached to a front end of the front side frame. The front side frame includes a compressive-deformation part which is configured to be compressively deformed in a vehicle frontal collision and extend rearward from the front end, having substantially the same sectional shape as the crash can. A gusset member for preventing shearing deformation of the closed cross section of the front side frame is provided at a portion of the front side frame between the mount-bracket attachment part and the compressive-deformation part.

[OBJECT] To provide a hydraulic drive system for a dump truck, which can prevent an excessive increase in engine rotation speed upon operation of a truck body.

[MEANS FOR ACHIEVING THE OBJECT] A hydraulic drive system is provided with a generator 8 for outputting electricity corresponding to a rotation speed of an engine 7, an electric motor 11 drivable responsive to the electricity from the generator 8, hydraulic pumps 12a, 12b drivable by the electric motor 11, truck-body elevating cylinders 6 for pivoting a truck body 5 in an up-and-down direction, and a stroke detector 14 for detecting a stroke of the control apparatus of the truck-body elevating cylinders 6, and is also provided with a controller 19 for performing control of engine rotation speed. The controller 19 includes a motor electric-power computing means 19a for determining electric power for the electric motor 11, which corresponds to the stroke detected by the stroke detector 14, and a discrimination means 19b for discriminating whether or not the electricity from the generator 8 has become greater than the thus-determined electric power for the electric motor 1.

Systems and methods for reducing noise and vibration that may be associated with engine braking are presented. In one example, intake and exhaust valve timings are adjusted to reduce engine noise and vibration at lower engine braking request levels. The engine intake and exhaust valve timings increase compression engine braking and decrease engine expansion braking for higher engine braking request levels.

A method is provided for adjusting a fuel pressure in a high pressure fuel accumulator of an accumulator injection system of an internal combustion engine as a first drive motor which, together with a second drive motor, is situated in a drive train, in which variable torque contributions of the internal combustion engine and of the second drive motor are superposed, an actual value of the fuel pressure, which sets in in response to a lower torque contribution of the internal combustion engine in the high pressure fuel accumulator, deviating from a setpoint value specified for higher torque contributions and at which the actual value, in response to an increase in the torque contribution from the lower value to the higher torque contribution of the internal combustion engine being adjusted to its higher setpoint value. The method stands out in that the adjustment is performed so that a rate of a change in the actual value does not exceed a specified boundary value during the adjustment. A control device equipped to perform the method is also provided.