Abstract: A rotating detonation combustion (RDC) system is provided. The RDC includes a first outer wall and a second outer wall each extended around a centerline axis, and a detonation chamber formed radially inward of the second outer wall. A fuel passage extended between the first outer wall and the second outer wall, the fuel passage including a first inlet opening proximate to the aft end through which a flow of fuel is received into the fuel passage. The flow of fuel is provided through the fuel passage from the aft end to the forward end of the RDC system and to the detonation chamber.

Abstract: A fuel and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

Abstract: Systems for rotating detonation combustion are provided herein. The system includes an inner wall and an outer wall each extended around a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall, and an iterative structure positioned at one or both of the inner wall or the outer wall. The iterative structure includes a first threshold structure corresponding to a first pressure wave attenuation and a second threshold structure corresponding to a second pressure wave attenuation. The iterative structure provides for pressure wave strengthening along a first circumferential direction in the detonation chamber or pressure wave weakening along a second circumferential direction opposite of the first circumferential direction. The first circumferential direction corresponds to a desired direction of pressure wave propagation in the detonation chamber.

Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.

Abstract: Various methods and systems are provided for skip-firing an engine. As one embodiment, a method for an engine includes firing all cylinders of the engine and not altering the closing timing of the intake valves when fueling demands are greater than a threshold. The method further includes skip-firing the engine when fueling demands are less than a threshold, and holding open the intake valves of skipped cylinders for a greater duration than intake valves of firing cylinders.

Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.

Abstract: A vehicle control system examines characteristics of an upcoming segment of a trip of a hybrid vehicle. One or more locations in the upcoming segment of the trip are identified based on the characteristics as places where an engine of the vehicle is incapable of generating enough energy to power the vehicle through the locations. Operational settings of the vehicle are calculated based on the locations to operate the vehicle in a way that charges an energy storage device with energy that can be used to replace or supplement the energy provided by the engine to propel the hybrid vehicle over or through the locations. The one or more processors are configured to one or more of automatically control or generate a control signal for automated operation of the hybrid vehicle according to the one or more operational settings that are calculated.

Abstract: A control system for an engine includes one or more processors configured to determine when a change in one or more of oxygen or fuel supplied to an engine. The one or more processors also are configured to, responsive to determining the change in oxygen and/or fuel supplied to an engine, direct one or more fuel injectors of the engine to begin injecting fuel into one or more cylinders of the engine during both a first fuel injection and a second fuel injection during each cycle of a multi-stroke engine cycle of the one or more cylinders.

Abstract: Various methods and systems are provided for skip-firing an engine. As one embodiment, a method for an engine includes firing all cylinders of the engine and not altering the closing timing of the intake valves when fueling demands are greater than a threshold. The method further includes skip-firing the engine when fueling demands are less than a threshold, and holding open the intake valves of skipped cylinders for a greater duration than intake valves of firing cylinders.

Abstract: A system for controlling a hybrid propulsion system includes a computer programmed to obtain altitude and terrain information associated with a predetermined route for the hybrid propulsion system comprising a first energy source and a second energy source. The computer is also programmed to obtain current and forecast ambient weather information associated with the predetermined route of the hybrid propulsion system, determine a power requirement and a torque requirement of the hybrid propulsion system associated with the altitude and the terrain along the predetermined route of the hybrid propulsion system, generate a trip plan to optimize at least one of a plurality of performance parameters of the hybrid propulsion system as the hybrid propulsion system travels along the predetermined route, and preferentially select the first energy source and/or the second energy source based on the trip plan.

Abstract: A fuel and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas (e.g., air) from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also includes one or more upper channels and one or more lower channels that are configured to provide a substantially similar amount of flow relative to each other to the interior volume The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

Abstract: A combustion system includes an annular tube disposed between an inner wall and an outer wall, the annular tube extending from an inlet end to an outlet end; at least one fluid inlet disposed in the annular tube proximate the inlet end, the fluid inlet providing a conduit through which fluid flows into the annular tube; at least one outlet disposed in the annular tube proximate the outlet end; and at least one cooling feature disposed at an underside of the inner wall or the outer wall. The cooling feature maintains a temperature of the inner wall or the outer wall within a predetermined range.

Abstract: A combustion system includes an annular tube disposed between an inner wall and an outer wall, the annular tube extending from an inlet end to an outlet end; at least one fluid inlet disposed in the annular tube proximate the inlet end, the fluid inlet providing a conduit through which fluid flows into the annular tube; at least one outlet disposed in the annular tube proximate the outlet end; at least one primary fuel injector, the primary fuel injector dispersing fuel into a fluid stream entering the annular tube via the fluid inlet; and at least one secondary fuel injector, the secondary fuel injector disposed in the annular tube.

Abstract: A method involves receiving a plurality of engine parameters and a sensed ambient operating condition during operation of an engine and determining a current substitution rate based on the plurality of engine parameter. The method also involves determining at least one of a pre-combustion temperature and an end gas temperature based on the plurality of engine parameters and the sensed ambient operating condition and determining a maximum substitution rate based on at least one of the pre-combustion temperature and the end gas temperature. The method further involves comparing the current substitution rate with the maximum substitution rate and controlling at least one engine parameter among the plurality of engine parameters if the current substitution rate is different from the maximum substitution rate so as to generate the current substitution rate to less than or equal to the maximum substitution rate.

Abstract: Various systems and methods are provided for controlling operation of a turbocharger compressor. In one example, a system includes a turbocharger including a turbine positioned in an exhaust passage and a compressor positioned in an intake passage, an engine bypass passage having an inlet fluidically coupled to an outlet of the compressor and an outlet fluidically coupled to an inlet of the turbine, an engine bypass valve to control flow through the engine bypass passage, and a controller configured to adjust a position of the engine bypass valve to maintain compressor operation within a designated compressor efficiency region.

Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.

Abstract: A vehicle control system examines characteristics of an upcoming segment of a trip of a hybrid vehicle. One or more locations in the upcoming segment of the trip are identified based on the characteristics as places where an engine of the vehicle is incapable of generating enough energy to power the vehicle through the locations. Operational settings of the vehicle are calculated based on the locations to operate the vehicle in a way that charges an energy storage device with energy that can be used to replace or supplement the energy provided by the engine to propel the hybrid vehicle over or through the locations. The one or more processors are configured to one or more of automatically control or generate a control signal for automated operation of the hybrid vehicle according to the one or more operational settings that are calculated.

Abstract: A method for use with an internal combustion engine having both donor and non-donor cylinder groups includes: injecting a fuel in one, or both, of the groups; injecting a second fuel in both groups at a first substitution rate; recirculating an exhaust emission from the donor cylinder group to both groups; combusting a mixture of air, the first fuel, the second fuel and the exhaust emission in both cylinder groups; and lowering the substitution rate of the second fuel in one, or both, of the cylinder groups. Other methods of controlling an engine and a system are also disclosed.

Abstract: A fuel and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.