Methods and systems for controlling a pneumatic starter air valve of a gas turbine engine are described herein. The starter air valve is controlled in a first mode of operation by actuating a first solenoid of the starter air valve with a steady-state input signal. Passage of the steady-state input signal to a second solenoid of the starter air valve is allowed, to actuate the second solenoid and enable pressure regulation of the starter air valve. The starter air valve is controlled in a second mode of operation by actuating the first solenoid with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid is prevented, to disable the pressure regulation in the second mode of operation.

Methods and systems for controlling a pneumatic starter air valve of a gas turbine engine are described herein. The starter air valve is controlled in a first mode of operation by actuating a first solenoid of the starter air valve with a steady-state input signal. Passage of the steady-state input signal to a second solenoid of the starter air valve is allowed, to actuate the second solenoid and enable pressure regulation of the starter air valve. The starter air valve is controlled in a second mode of operation by actuating the first solenoid with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid is prevented, to disable the pressure regulation in the second mode of operation.

Methods and systems for controlling a pneumatic starter air valve of a gas turbine engine are described herein. The starter air valve is controlled in a first mode of operation by actuating a first solenoid of the starter air valve with a steady-state input signal. Passage of the steady-state input signal to a second solenoid of the starter air valve is allowed, to actuate the second solenoid and enable pressure regulation of the starter air valve. The starter air valve is controlled in a second mode of operation by actuating the first solenoid with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid is prevented, to disable the pressure regulation in the second mode of operation.

A spark-ignition direct fuel injection valve includes, at least, a seat member provided with a fuel injection hole and a valve seat and a valve body which controls fuel injection from the injection hole by contacting and separating from the valve seat. In the spark-ignition direct fuel injection valve: the injection hole has an injection hole inlet which is open inwardly of the seat member and an injection hole outlet which is open outwardly of the seat member; an opening edge of the injection hole inlet has a first round-chamfered portion formed on an upstream side with respect to a fuel flow toward the injection hole inlet; and an extending length (L) of the injection hole does not exceed three times a hole diameter (D) of the injection hole.

A spark-ignition direct fuel injection valve includes, at least, a seat member provided with a fuel injection hole and a valve seat and a valve body which controls fuel injection from the injection hole by contacting and separating from the valve seat. In the spark-ignition direct fuel injection valve: the injection hole has an injection hole inlet which is open inwardly of the seat member and an injection hole outlet which is open outwardly of the seat member; an opening edge of the injection hole inlet has a first round-chamfered portion formed on an upstream side with respect to a fuel flow toward the injection hole inlet; and an extending length (L) of the injection hole does not exceed three times a hole diameter (D) of the injection hole.

A metering system for a fluid atomizer includes a housing, first and second metering members, and at least one solenoid. The housing includes a mixing chamber. The first metering member is operable to control flow of a first fluid to the mixing chamber. The second metering member is arranged coaxial with the first metering member and operable to control flow of a second fluid to the mixing chamber. The at least one solenoid is configured to operate at least one of the first and second metering members.

A metering system for a fluid atomizer includes a housing, first and second metering members, and at least one solenoid. The housing includes a mixing chamber. The first metering member is operable to control flow of a first fluid to the mixing chamber. The second metering member is arranged coaxial with the first metering member and operable to control flow of a second fluid to the mixing chamber. The at least one solenoid is configured to operate at least one of the first and second metering members.

Disclosed is an air-assisted fuel injection system, comprising a cylindrical bore; a plunger and a barrel within the cylindrical bore, the plunger having a flat surface; and a securing means abutting against the flat surface to keep the plunger from rotating within the cylindrical bore.

Disclosed is an air-assisted fuel injection system, comprising a cylindrical bore; a plunger and a barrel within the cylindrical bore, the plunger having a flat surface; and a securing means abutting against the flat surface to keep the plunger from rotating within the cylindrical bore.

A fuel system for an internal combustion engine includes a common rail and a plurality of fuel injectors connected to the common rail and each including an outlet check, an injection control valve, and an injection rate controller. The injection rate controller varies a flow area to a nozzle of the fuel injector such that a pressure drop through the fuel injector is varied to provide injection rate shaping.