Intake noise suppression techniques for a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system configured to recirculate exhaust gas produced by the engine to an intake system of the engine via an EGR port comprise receiving, from a mass air flow (MAF) sensor of the engine, a MAF signal indicative of measured airflow through the intake system, detecting, based on the MAF signal, intake system conditions that are indicative of audible noise, and in response to detecting the detected intake system conditions that are indicative of audible noise, at least partially closing a differential pressure (dP) valve to mitigate or eliminate the intake system conditions and the corresponding audible noise, wherein the MAF sensor is disposed in the intake system upstream from the dP valve.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

Intake noise suppression techniques for a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system configured to recirculate exhaust gas produced by the engine to an intake system of the engine via an EGR port comprise receiving, from a mass air flow (MAF) sensor of the engine, a MAF signal indicative of measured airflow through the intake system, detecting, based on the MAF signal, intake system conditions that are indicative of audible noise, and in response to detecting the detected intake system conditions that are indicative of audible noise, at least partially closing a differential pressure (dP) valve to mitigate or eliminate the intake system conditions and the corresponding audible noise, wherein the MAF sensor is disposed in the intake system upstream from the dP valve.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

An aircraft propulsor that includes an exhaust combustor is disclosed. The aircraft propulsor can include an internal combustion engine and a turbocharger. The turbocharger can be spooled while motoring the internal combustion engine. For example, when restarting the internal combustion engine at high altitude, an injector and an igniter can provide fuel to the exhaust and combust fuel to spool the turbocharger, decreasing load on the engine during restarting. In another example, an electric turbocharger can be driven with an electric motor to spool the turbocharger.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

An aircraft propulsor that includes an exhaust combustor is disclosed. The aircraft propulsor can include an internal combustion engine and a turbocharger. The turbocharger can be spooled while motoring the internal combustion engine. For example, when restarting the internal combustion engine at high altitude, an injector and an igniter can provide fuel to the exhaust and combust fuel to spool the turbocharger, decreasing load on the engine during restarting. In another example, an electric turbocharger can be driven with an electric motor to spool the turbocharger.

A fuel injector and method are disclosed including an injector body with a fuel sac, and an end positioned into a combustion chamber. A main fuel passage, having a varying cross-sectional area forming a reduced pressure region, fluidically couples the fuel sac to the combustion chamber. One or more additional passages fluidically couple the reduced pressure region with one or both of the fuel sac and the combustion chamber.

A fuel injector and method are disclosed including an injector body with a fuel sac, and an end positioned into a combustion chamber. A main fuel passage, having a varying cross-sectional area forming a reduced pressure region, fluidically couples the fuel sac to the combustion chamber. One or more additional passages fluidically couple the reduced pressure region with one or both of the fuel sac and the combustion chamber.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.