Abstract: A method for extending thermodynamic turbine mapping of a turbocharger, the turbocharger including a turbine and a compressor, the method including the steps of providing a steady-state turbocharger gas test stand configured to flow continuous gas to the turbocharger, the test stand including a throttle device disposed upstream of an inlet of the compressor of the turbocharger, and varying an area of the inlet with the throttle device to change density of the continuously flowing gas at the inlet of the compressor and establish a choked-flow condition for extending the thermodynamic turbine mapping of the turbocharger.

Abstract: High pressure loop exhaust gas circulation is achieved in an exhaust system (10) of an engine (12) by providing an adjustable valve (100) in an exhaust passage (18) of the engine (12). The valve (100) is configured to control fluid flow through the passage (18) and generate pressure to drive the high pressure exhaust gas recirculation. The valve (100) includes a valve inner surface (110) that has a curvilinear profile when viewed in longitudinal cross section. An actuator (140) is connected to the valve (100), and is configured to move the valve (100) relative to the exhaust passage (18) so as to control exhaust gas pressure within the exhaust passage (18). In some embodiments, a pilot tube (280) is used in combination with the valve (100) to generate high pressure exhaust gas recirculation at the engine (12) intake.

Abstract: A method for extending thermodynamic turbine mapping of a turbocharger, the turbocharger including a turbine and a compressor, the method including the steps of providing a steady-state turbocharger gas test stand configured to flow continuous gas to the turbocharger, the test stand including a throttle device disposed upstream of an inlet of the compressor of the turbocharger, and varying an area of the inlet with the throttle device to change density of the continuously flowing gas at the inlet of the compressor and establish a choked-flow condition for extending the thermodynamic turbine mapping of the turbocharger.

Abstract: High pressure loop exhaust gas circulation is achieved in an exhaust system (10) of an engine (12) by providing an adjustable valve (100) in an exhaust passage (18) of the engine (12). The valve (100) is configured to control fluid flow through the passage (18) and generate pressure to drive the high pressure exhaust gas recirculation. The valve (100) includes a valve inner surface (110) that has a curvilinear profile when viewed in longitudinal cross section. An actuator (140) is connected to the valve (100), and is configured to move the valve (100) relative to the exhaust passage (18) so as to control exhaust gas pressure within the exhaust passage (18). In some embodiments, a pilot tube (280) is used in combination with the valve (100) to generate high pressure exhaust gas recirculation at the engine (12) intake.