Abstract: An apparatus and method for controlling exhaust gas recirculation flow. The apparatus and method uses a pressure-bleeding device, such as a wastegate valve, to change the pressure in an internal combustion engine in order to alter the flow rate of the exhaust gas through an exhaust gas recirculation conduit. In one form, the invention includes an inlet conduit connected to an intake manifold of an internal combustion engine and an exhaust conduit connected to exhaust manifold of an internal combustion engine. The pressure-bleeding device is operatively coupled to the intake conduit. Altering the pressure in the intake conduit changes the pressure across the entire system. This change in pressure in the entire system results in a change in pressure across the exhaust gas recirculation conduit. Therefore, a flow is created through the exhaust gas recirculation conduit and can be controlled using the intake side pressure bleeding device.

Abstract: A method for controlling a variable geometry turbine of a turbocharger to increase the temperature of the exhaust gas delivered to an after-treatment system. In one form the method includes reducing a fluid flow area to the turbine below a normal size and bypassing a portion of the exhaust gas around a plurality of guide vanes.

Abstract: A method for controlling a variable geometry turbine of a turbocharger to increase the temperature of the exhaust gas delivered to an after-treatment system. In one form the method includes reducing a fluid flow area to the turbine below a normal size and bypassing a portion of the exhaust gas around a plurality of guide vanes.

Abstract: A passive engine exhaust flow restriction arrangement includes a fixed geometry flow restriction mechanism disposed in line with an exhaust conduit. In one embodiment, the flow restriction mechanism is disposed upstream of a turbocharger turbine, and in an alternate embodiment it is disposed downstream of the turbine. In either case, the flow restriction mechanism defines a fixed cross sectional flow area therethrough that is less than the cross sectional flow area of the exhaust conduit. Preferably, the cross sectional flow area of the flow restriction mechanism is sized to optimize one, or both, of turbine efficiency and engine fuel economy.

Abstract: A passive engine exhaust flow restriction arrangement includes a fixed geometry flow restriction mechanism disposed in line with an exhaust conduit. In one embodiment, the flow restriction mechanism is disposed upstream of a turbocharger turbine, and in an alternate embodiment it is disposed downstream of the turbine. In either case, the flow restriction mechanism defines a fixed cross sectional flow area therethrough that is less than the cross sectional flow area of the exhaust conduit. Preferably, the cross sectional flow area of the flow restriction mechanism is sized to optimize one, or both, of turbine efficiency and engine fuel economy.

Abstract: A system for estimating turbocharger compressor outlet temperature includes an engine controller responsive to any two of corrected turbocharger speed, corrected fresh mass air flow and turbocharger compressor pressure ratio (compressor outlet pressure/compressor inlet pressure) to compute compressor outlet temperature based on a corresponding compressor outlet temperature model.

Abstract: An exhaust gas recirculation (EGR) enhancement system for a turbocharged internal combustion engine includes a throttle valve arranged in the exhaust duct of the engine, downstream of the EGR system. The throttle valve is controlled in response to engine load and engine speed to selectively provide back pressure upstream of the throttle valve to selectively drive an EGR exhaust flow through an EGR duct to the intake manifold. An embodiment of the EGR system includes a cooler that lowers the temperature of the EGR exhaust flow to provide better reductions in nitric oxide emissions. The exhaust turbine of the turbocharger may be of the fixed geometry type or the variable geometry type to provide a turbine with a fixed or variable swallowing capacity. The fixed geometry turbine is preferably equipped to allow excess pressure to be released through a wastegate duct arranged in fluid parallel with the exhaust turbine, thereby allowing for higher power and higher speeds.

Abstract: An exhaust gas recirculation (EGR) enhancement system for a turbocharged internal combustion engine includes a throttle valve arranged in the exhaust duct of the engine, downstream of the EGR system. The throttle valve is controlled in response to engine load and engine speed to selectively provide back pressure upstream of the throttle valve to selectively drive an EGR exhaust flow through an EGR duct to the intake manifold. An embodiment of the EGR system includes a cooler that lowers the temperature of the EGR exhaust flow to provide better reductions in nitric oxide emissions. The turbine is equipped to allow excess pressure to be released through a wastegate duct arranged in fluid parallel with the exhaust turbine, thereby allowing for higher power and higher speeds.

Abstract: An exhaust gas recirculation (EGR) enhancement system for a turbocharged internal combustion engine includes a throttle valve arranged in the exhaust duct of the engine, downstream of the EGR system. The throttle valve is controlled in response to engine load and engine speed to selectively provide back pressure upstream of the throttle valve to selectively drive an EGR exhaust flow through an EGR duct to the intake manifold. An embodiment of the EGR system includes a cooler that lowers the temperature of the EGR exhaust flow to provide better reductions in nitric oxide emissions. The turbine is equipped to allow excess pressure to be released through a wastegate duct arranged in fluid parallel with the exhaust turbine, thereby allowing for higher power and higher speeds.

Abstract: A turbomachine, operable as a compressor or a turbine, for a compressible fluid is provided which includes a wheel having a plurality of vanes extending from a generally axial flow section to a generally radial flow section. Adjacent vanes define fluid passageways having a generally axially oriented section and a generally radially oriented section. Located substantially within the generally radially oriented sections of a predetermined number of passageways is a reference station which has a configuration such that the mean tangential dimension of said passageway at said reference station is no more than about 60% of the circumference of the rotor at that mean radius divided by the number of vanes at that radius. Each reference station serves to effect substantial attachment of the flowing fluid to the surfaces defining said passageway, particularly at low mass flow, and, thus, broaden the usable flow range of the turbomachine.

Abstract: A turbomachine for a compressible fluid is provided which includes a compressor wheel having a plurality of vanes extending from a generally axial flow inlet to a generally radial flow outlet. Adjacent vanes define fluid passageways having a generally axially oriented section near the inlet and a generally radially oriented section near the outlet. Located substantially within the generally radially oriented sections of a predetermined number of passageways is a reference station which has a configuration such that the mean tangential dimension of said passageway at said reference station is no more than about 60% of the circumference of the rotor at that mean radius divided by the number of vanes at that radius. Each reference station serves to effect substantial attachment of the flowing fluid to the surfaces defining said passageway, particularly at low mass flow, and, thus, broaden the usable flow range of the compressor.