Two-stroke uniflow turbo-compound internal combustion engine

A method for operating a radial internal combustion (IC) engine that includes a multiple, radially-arranged reciprocating two-stroke uniflow cylinders, the IC engine including a high pressure supercharger inlet air system that includes a high pressure compressor, and each cylinder includes a cylinder wall and a cylinder head, the cylinder head having an exhaust port, a fuel injector and a spark means disposed through the cylinder head, a piston reciprocally mounted in the cylinder for movement alternately through compression and power strokes, and an air inlet including one or more swirl ports disposed through the cylinder wall and entering the cylinder chamber tangentially with respect to the axial centerline of the cylinder, and wherein the one or more swirl ports are opened and closed in response to movement of said piston, the method comprising repeating a cylinder cycle, the cycle comprising the steps of:

• a) compressing ambient air and passing the pressurized inlet air in a circumferential direction into an annular inlet air manifold, b) directing a portion of the pressurized inlet air out of the annular inlet air manifold, through an uncovered swirl port, and into the cylinder with the piston proximate the bottom of its reciprocal stroke within the cylinder, and swirling the inlet air in tangential, turbulent, unidirectional flow within the cylinder, c) maintaining the exhaust port in an open position while the inlet air ports are uncovered to provide scavenging of the cylinder by the inlet air, d) advancing the piston upward to cover the inlet ports, e) closing the exhaust port, f) compressing the inlet air between the piston and the cylinder head, g) dispersing a fuel near the end of the compression stroke at a lean burning fuel to air ratio of about 0.2 to about 0.8, relative to a stoicheometric fuel to air ratio of 1:1, the fuel being dispersed in the same tangential direction as the flow of the turbulent, swirling air, to obtain a stratified charge and intimate air-fuel mixing, h) spark igniting and combusting the stratified charge of the air-fuel mixture to initiate the power stroke, i) opening the exhaust port near the end of the power stroke to exhaust pressurized combustion gases, and j) uncovering the inlet ports as the piston approaches the bottom of its power stroke.

A method for operating a reciprocating two-stroke uniflow multiple cylinder internal combustion (IC) engine with a low pressure positive displacement inlet air compressor that provides an outlet:inlet pressure ratio of up to 4:1, the engine including a plurality of a cylinder that includes a cylinder wall and a cylinder head having an exhaust port, an exhaust valve disposed in the exhaust port, a fuel injector and a spark means disposed through the cylinder head, a piston mounted in the cylinder for reciprocal movement between a top dead center (TDC) position and a bottom dead center (BDC) position, and through a compression stroke and a power stroke, and at least one swirl inlet port passing through the cylinder wall at the bottom of the cylinder, and oriented tangential to an axial centerline of the cylinder, wherein the at least one swirl port is covered and uncovered in response to the reciprocal movement of the piston;

• the method comprising repeating a cylinder cycle, the cycle comprising the steps of:
• a) passing low pressure inlet air through the uncovered one or more swirl ports and into the cylinder with the piston proximate the bottom of its reciprocal stroke within the cylinder, and swirling the inlet air in tangential turbulent unidirectional flow within the cylinder wherein the mass quantity of inlet air is proportional to the engine revolution speed, b) maintaining the exhaust port in an open position while the inlet air ports are uncovered to provide scavenging of the cylinder by the inlet air, c) advancing the piston upward to cover the inlet ports, d) closing the exhaust port, e) compressing the inlet air between the piston and the cylinder head, preferably to a compression ratio of about 8:1 to about 12:1, f) dispersing a fuel near the end of the compression stroke at a lean burning fuel to air ratio in the range of about 0.2 to about 0.8, relative to a stoicheometric fuel to air ratio of 1:1, the fuel being dispersed in the same tangential direction as the flow of the turbulent, swirling air, to obtain a stratified charge and intimate air-fuel mixing, g) spark igniting and combusting the stratified charge of the air-fuel mixture to initiate the power stroke, h) opening the exhaust port near the end of the power stroke to exhaust pressurized combustion gases, and i) uncovering the inlet ports as the piston approaches the bottom of its power stroke.