Embodiments of apparatus for affecting air flow and/or pressure wave propagation in relation to an audio source enclosure are disclosed. The apparatus may include two waveguide sections mounted within an audio source enclosure. The waveguide sections may include complementary nested first and second funnels disposed relative to each other in a manner to channel air flow in and/or from the enclosure.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

A piston for use in a GDCI engine cooperates with the wall of a cylinder defined in the engine and with a cylinder head to define a combustion chamber. The surface of the piston that faces the cylinder head defines a bowl that is configured to receive fuel that is dispensed from a fuel injector that is located in the cylinder head substantially along the central axis of the cylinder. The bowl is configured such that substantially all of the injected fuel associated with a combustion event reaches a localized equivalence ratio greater than 0.0 and less than or equal to 1.2 at a time immediately preceding initiation of the combustion event.

An electron generation means for generating electrons includes a rectifier circuit and a booster circuit. AC power from a power supply is passed through the rectifier circuit in advance and then flown to the booster circuit. The rectifier circuit, according to the plus/minus inversion cycle of the said AC power, blocks current flowing toward a second terminal in a state where a first terminal of the rectifier circuit has a positive potential, and current flows from the second terminal only in the state where the first terminal of the rectifier circuit has a negative potential, and thus current flows only in one direction of the alternating current. The booster circuit boosts the voltage on a primary side, and electrons are generated from one terminal on a secondary side of the booster circuit only in a state where the first terminal of the rectifier circuit has a negative potential.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

A fuel injection device is provided with reduced adherence of fuel spray with respect to an intake valve, a wall surface in an engine cylinder, or a piston. The fuel injection device includes a valve body and a seat surface to perform sealing of fuel cooperatively and injection holes. Inlet opening surfaces are formed on the seat surface. A first injection hole and a second injection hole arranged closest to the first injection hole. The first injection hole is larger than the second injection hole in an injection hole angle to be an angle formed by a normal direction of the seat surface and a center axis of the injection hole. The second injection hole is larger than the first injection hole in an area of a cross-section perpendicular to the center axis of the injection hole.

The invention relates to an internal combustion engine and to a method for operating the internal combustion engine, which has at least one cylinder having a combustion chamber, the combustion chamber being bounded by a cylinder roof, a cylinder wall and a movable cylinder piston, a multi-hole injection nozzle and a spark plug being arranged in a central position in the cylinder roof, the multi-hole injection nozzle injecting fuel into the combustion chamber at injection pressures of >/=300 bar by means of a plurality of injection jets. It is provided that at least one injection jet (i>/=1) injects fuel into a three-dimensional space within the combustion chamber on the intake side, which space lies below an opening of at least one intake valve (104A, 104B) with respect to the direction of the longitudinal central axis (Z) of the cylinder, and at least four injections jets (i>/=4) inject fuel into a three-dimensional space of the combustion chamber on the exhaust side, which space lies below an opening of at least one exhaust valve (105A, 105B).

An internal combustion gas engine (2) is disclosed. It includes a cylinder arrangement (4) and a first compressor (6) for compressing a gaseous fuel and air mixture. The at least one cylinder arrangement (4) forms a combustion chamber (8) and includes an intake arrangement (10) for intake of charge gas, a sparkplug (12), and a pre-chamber (14). The engine (2) comprises a second compressor (16) for compressing a gaseous medium, and a pressure reducer (18). An outlet (20) of the first compressor (6) is arranged in parallel with an outlet (22) of the second compressor (16). The outlet (20) of the first compressor (6) is connected to the pre-chamber (14). The outlet (20) of the first compressor (6) and the outlet (22) of the second compressor (16) are connected to the pressure reducer (18). An outlet (24) of the pressure reducer (18) is connected to the intake arrangement (10).