Abstract: The subject matter of this specification can be embodied in, among other things, a method of igniting an air/fuel mixture in an internal combustion engine includes receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter, igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, directing the flame to eject the pre-combustion chamber through a collection of passages in a wall of the pre-combustion chamber, toward a peripheral wall of a main combustion chamber of the internal combustion engine, igniting, by the flame, air/fuel mixture in the main combustion chamber adjacent the peripheral wall, and then igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of the ignited air/fuel mixture or a portion of the directed flame adjacent the peripheral wall.

Abstract: A housing defines a gaseous fuel inlet and a gaseous fuel outlet. A rotor defines an internal flow passage therethrough that rotates with the rotor to, alternately, allow gaseous fuel flow, or to block gaseous fuel flow, between the inlet and the outlet, based on a position of the rotor. A seal is biased to abut an exterior surface of the rotor. The seal is between the rotor and the outlet. An actuator is rotably coupled to the rotor. The driver is configured to rotate the rotor. A controller is in communication with the driver and is configured to control the driver to rotate at a rate based on an engine speed of the engine.

Abstract: A housing defines a gaseous fuel inlet and a gaseous fuel outlet. A rotor defines an internal flow passage therethrough that rotates with the rotor to, alternately, allow gaseous fuel flow, or to block gaseous fuel flow, between the inlet and the outlet, based on a position of the rotor. A seal is biased to abut an exterior surface of the rotor. The seal is between the rotor and the outlet. An actuator is rotably coupled to the rotor. The driver is configured to rotate the rotor. A controller is in communication with the driver and is configured to control the driver to rotate at a rate based on an engine speed of the engine.

Abstract: The subject matter of this specification can be embodied in, among other things, a method of igniting an air/fuel mixture in an internal combustion engine includes receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter, igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, directing the flame to eject the pre-combustion chamber through a collection of passages in a wall of the pre-combustion chamber, toward a peripheral wall of a main combustion chamber of the internal combustion engine, igniting, by the flame, air/fuel mixture in the main o combustion chamber adjacent the peripheral wall, and then igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of the ignited air/fuel mixture or a portion of the directed flame adjacent the peripheral wall.

Abstract: The subject matter of this specification can be embodied in, among other things, a method of igniting an air/fuel mixture in an internal combustion engine includes receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter, igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, directing the flame to eject the pre-combustion chamber through a collection of passages in a wall of the pre-combustion chamber, toward a peripheral wall of a main combustion chamber of the internal combustion engine, igniting, by the flame, air/fuel mixture in the main combustion chamber adjacent the peripheral wall, and then igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of the ignited air/fuel mixture or a portion of the directed flame adjacent the peripheral wall.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: A convergent nozzle is in a mixer housing and in a flow path from an air inlet of the mixer to an outlet of the mixer. A convergent-divergent nozzle is in the mixer housing and includes an air-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle and from the interior of the exhaust gas housing. A first nozzle module is configured to be received in the mixer housing and, when received in the mixer housing, define at least a portion of the convergent nozzle or the convergent-divergent nozzle. A second nozzle module is configured to be received in the mixer housing separate from the first nozzle module. The second nozzle module, when received in the mixer housing, is configured to define at least a portion of the convergent or the convergent-divergent nozzle. The second nozzle module has a different flow characteristic than the first nozzle module.

Abstract: The subject matter of this specification can be embodied in, among other things, a method of igniting an air/fuel mixture in an internal combustion engine includes receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter, igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, directing the flame to eject the pre-combustion chamber through a collection of passages in a wall of the pre-combustion chamber, toward a peripheral wall of a main combustion chamber of the internal combustion engine, igniting, by the flame, air/fuel mixture in the main combustion chamber adjacent the peripheral wall, and then igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of the ignited air/fuel mixture or a portion of the directed flame adjacent the peripheral wall.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: A convergent nozzle is in a mixer housing and in a flow path from an air inlet of the mixer to an outlet of the mixer. A convergent-divergent nozzle is in the mixer housing and includes an air-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle and from the interior of the exhaust gas housing. A first nozzle module is configured to be received in the mixer housing and, when received in the mixer housing, define at least a portion of the convergent nozzle or the convergent-divergent nozzle. A second nozzle module is configured to be received in the mixer housing separate from the first nozzle module. The second nozzle module, when received in the mixer housing, is configured to define at least a portion of the convergent or the convergent-divergent nozzle. The second nozzle module has a different flow characteristic than the first nozzle module.