The invention relates to an internal combustion engine comprising a crankshaft, one or mor cylinders including a cylinder head, a piston, a combustion chamber, one or more intake valves, one or more exhaust valves, an intake system configured for feeding intake air to the engine, an exhaust system configured for conveying exhaust gas away from the engine, a pressure charging system connected to the intake system and an exhaust gas recirculation (EGR) system arranged to feed branched off exhaust gas from the exhaust system to the intake system via an EGR conduit wherein:—the internal combustion engine includes a valve actuation device configured to allow for late or early closing of the intake valves in accordance with late or early Miller-type valve timing, and wherein—the EGR system includes a gas feeding device configured to feed exhaust gas through the EGR conduit in modes of operation wherein the pressure in the intake system exceeds the pressure in the exhaust system. Additionally, a method of improving efficiency of an internal combustion engine is described.

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).

A hybrid-electric aerial vehicle is disclosed comprising: an airframe; a plurality of longitudinal booms extending radially from the airframe; a passively charged internal combustion engine operatively coupled with a fuel tank, a generator operatively coupled with the passively charged internal combustion engine; a battery bank operatively coupled with the generator; and a plurality of motors. The passively charged internal combustion engine has an intake engine valve, an exhaust engine valve, and a combustion chamber, wherein the intake engine valve is delayed to provide an expansion ratio in the combustion chamber that is greater than a compression ratio in the combustion chamber. Each of said plurality of motors may be positioned at a distal end of one of said plurality of longitudinal booms and be operatively coupled with a propeller, wherein the plurality of motors is electrically coupled with the battery bank and the generator.

The present invention relates to an internal-combustion engine comprising a combustion chamber provided with a single intake valve (2), a single exhaust valve (3), two plugs (4a, 4b) and a fuel injector (5). Furthermore, the combustion chamber comprises means for forming an aerodynamic swirling motion structure of the intake gas in the combustion chamber. Besides, fuel injector (5) is oriented so as to inject the fuel into the central area of the combustion chamber in the direction of the aerodynamic swirling motion structure.

The present invention relates to a combustion chamber of a combustion engine. The combustion chamber comprises a single intake valve (2), a single exhaust valve (3), a fuel injector (5) and two plugs (4). According to the invention, the combustion chamber is substantially elliptical (6) and the components of the combustion chamber are arranged as follows: valves (2, 3) are located at the ends of the major axis (8) of ellipse (6), plugs (4) are located close to the minor axis (9) of ellipse (6), fuel injector (5) is located on the periphery of ellipse (6) between intake valve (2) and a plug (4).

A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T.sub.1 through an inlet of a compressor having a pressure ratio of PR.sub.GT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature T.sub.BIC to a temperature T.sub.AIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio r.sub.VC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where

[00001]${\left({\mathrm{PR}}_{\mathrm{GT}}\right)}^a.Math.{\left(r_{\mathrm{VC}}\right)}^b.Math.\left(\frac{T_{\mathrm{AIC}}}{T_{\mathrm{BIC}}}\right).Math.\left(\frac{T_1}{T_A}\right)<1.$

An engine assembly is also discussed.

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).

A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T.sub.1 through an inlet of a compressor having a pressure ratio of PR.sub.GT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature T.sub.BIC to a temperature T.sub.AIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio r.sub.VC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ${\left({\mathrm{PR}}_{\mathrm{GT}}\right)}^a{\left(r_{\mathrm{VC}}\right)}^b\left(\frac{T_{\mathrm{AIC}}}{T_{\mathrm{BIC}}}\right)\left(\frac{T_1}{T_A}\right)<1.$
An engine assembly is also discussed.

A method of operating an internal combustion engine having pilot subchambers communicating with main combustion chambers, the internal combustion engine configured in use to deliver a main fuel injection of a maximum quantity of fuel to the main combustion chambers when the internal combustion engine is operated at maximum load. The method includes delivering a pilot fuel injection of at most 10% of the maximum quantity to the pilot subchambers, igniting the pilot fuel injection within the pilot subchambers, directing the ignited fuel from the pilot subchambers to the main combustion chambers, and delivering a main fuel injection of a main quantity of fuel to at least one of the main combustion chambers receiving the ignited fuel, with the main quantity being at most 10% of the maximum quantity.

An internal combustion engine with a cylinder head and at least one piston-cylinder unit, in which, in a cylinder, a piston can be moved between a bottom and a top dead center position, where, in the cylinder, between the piston and the cylinder head a main combustion chamber is formed, which communicates with a prechamber which has a prechamber gas valve, and where the intake and outlet valves of the main combustion chamber are actuated by an actuator, where the prechamber gas valve is connected to a source for a gas-air mixture and the prechamber charge consists of a gas-air mixture with a lambda higher than 1.2, preferably higher than 1.5 and particularly preferably higher than 1.7, and the actuator is configured such that the intake valve closes before the piston reaches the bottom dead center position, where the piston is designed as a flat piston.