Abstract: A stator blade for a centrifugal compressor having a front portion configured to generate one or more strear-wise vortices in the gas flow around the stator blade in order to avoid and/or delay a detachment of the gas flow from the suction surface of the stator blade especially when the centrifugal compressor is not operating at its operational design speed.

Abstract: A stator blade for a centrifugal compressor having a front portion configured to generate one or more strear-wise vortices in the gas flow around the stator blade in order to avoid and/or delay a detachment of the gas flow from the suction surface of the stator blade especially when the centrifugal compressor is not operating at its operational design speed.

Abstract: A turbomachinery apparatus includes: a turbine, including: a turbine component defining an arcuate flowpath surface; an array of axial-flow turbine airfoils extending from the flowpath surface, the turbine airfoils defining spaces therebetween; and a plurality of fences extending from the flowpath surface, in the spaces between the turbine airfoils, each fence having opposed concave and convex sides extending between a leading edge and a trailing edge, wherein the fences have a nonzero camber and a constant thickness, are axially located near the leading edges of adjacent turbine airfoils, and wherein at least one of a chord dimension of the fences and a span dimension of the fences is less than the corresponding dimension of the turbine airfoils.

Abstract: In order to reduce erosion of an impeller due to liquid droplets in an incoming flow of gas, the impeller comprises converging-diverging bottlenecks; the incoming flow passes through the bottlenecks so that the speed of the gas at the inlet of the impeller first suddenly and substantially increases and then suddenly and substantially decreases; furthermore, the impeller is configured so that, internally after its inlet, the incoming flow is deviated gradually in the meridional plane.

Abstract: A turbomachinery apparatus includes: a turbine, including: a turbine component defining an arcuate flowpath surface; an array of axial-flow turbine airfoils extending from the flowpath surface, the turbine airfoils defining spaces therebetween; and a plurality of fences extending from the flowpath surface, in the spaces between the turbine airfoils, each fence having opposed concave and convex sides extending between a leading edge and a trailing edge, wherein the fences have a nonzero camber and a constant thickness, are axially located near the leading edges of adjacent turbine airfoils, and wherein at least one of a chord dimension of the fences and a span dimension of the fences is less than the corresponding dimension of the turbine airfoils.

Abstract: An exhaust gas flow after-treatment (AT) system includes first AT device and a second AT device in fluid communication with and positioned in the flow of exhaust gas downstream of the first AT device. The AT system also includes an exhaust passage for carrying the flow of exhaust gas from the first AT device to the second AT device and an injector for introducing a reductant into the exhaust passage. The AT system additionally includes a variable-position mixer arranged within the exhaust passage downstream of the injector. Furthermore, the AT system includes a mechanism configured to regulate the variable-position mixer between and inclusive of a first mixer position configured to increase a swirling motion and turbulence in the exhaust gas flow within the exhaust passage to thereby mix the reductant with the exhaust gas flow, and a second mixer position configured to reduce a backpressure generated by the mixer.

Abstract: Systems and methods for controlling a valve for directing an exhaust gas stream through an exhaust duct having a first after treatment device and a second after treatment device in an exhaust system. The method includes receiving sensor signals from a sensor coupled to the second after treatment device. The method includes processing the sensor signals to determine a temperature of the second after treatment device, and determining a position for the valve based on whether the temperature exceeds a pre-defined threshold for the temperature of the second after treatment device. The method includes outputting a control signal to move the valve to a first position in which the exhaust gas stream flows through a first portion of the first after treatment device or a second position in which the exhaust gas stream flows through a second portion of the first after treatment device based on the temperature.

Abstract: An exhaust gas flow after-treatment (AT) system includes first and second AT devices. The first AT device includes cone with an inlet defined by a surface area having a first geometric center and an outlet defined by a surface area having a second geometric center. The AT system also includes an exhaust passage for carrying the exhaust gas flow from the first AT device cone outlet to the second AT device, and includes an injector for introducing a reductant into the exhaust gas flow within the exhaust passage. The first geometric center is arranged at a predetermined distance from the second geometric center and the inlet surface area is greater than the outlet surface area by a predetermined ratio. The predetermined distance and the predetermined ratio are together configured to induce swirl in and mix the reductant with the exhaust gas flow within the exhaust passage.

Abstract: An exhaust gas flow after-treatment (AT) system includes first AT device and a second AT device in fluid communication with and positioned in the flow of exhaust gas downstream of the first AT device. The AT system also includes an exhaust passage for carrying the flow of exhaust gas from the first AT device to the second AT device and an injector for introducing a reductant into the exhaust passage. The AT system additionally includes a variable-position mixer arranged within the exhaust passage downstream of the injector. Furthermore, the AT system includes a mechanism configured to regulate the variable-position mixer between and inclusive of a first mixer position configured to increase a swirling motion and turbulence in the exhaust gas flow within the exhaust passage to thereby mix the reductant with the exhaust gas flow, and a second mixer position configured to reduce a backpressure generated by the mixer.

Abstract: An exhaust gas flow after-treatment (AT) system includes first and second AT devices. The first AT device includes cone with an inlet defined by a surface area having a first geometric center and an outlet defined by a surface area having a second geometric center. The AT system also includes an exhaust passage for carrying the exhaust gas flow from the first AT device cone outlet to the second AT device, and includes an injector for introducing a reductant into the exhaust gas flow within the exhaust passage. The first geometric center is arranged at a predetermined distance from the second geometric center and the inlet surface area is greater than the outlet surface area by a predetermined ratio. The predetermined distance and the predetermined ratio are together configured to induce swirl in and mix the reductant with the exhaust gas flow within the exhaust passage.

Abstract: Systems and methods for controlling a valve for directing an exhaust gas stream through an exhaust duct having a first after treatment device and a second after treatment device in an exhaust system. The method includes receiving sensor signals from a sensor coupled to the second after treatment device. The method includes processing the sensor signals to determine a temperature of the second after treatment device, and determining a position for the valve based on whether the temperature exceeds a pre-defined threshold for the temperature of the second after treatment device. The method includes outputting a control signal to move the valve to a first position in which the exhaust gas stream flows through a first portion of the first after treatment device or a second position in which the exhaust gas stream flows through a second portion of the first after treatment device based on the temperature.

Abstract: An after-treatment (AT) system for an exhaust gas flow from an internal combustion engine includes first and second AT devices positioned in the exhaust gas flow. The AT system also includes an exhaust passage for carrying the flow of exhaust gas from the first AT device to the second AT device. The AT system additionally includes an injector configured to generate a reductant spray into the exhaust passage and a sensor positioned proximate the injector for detecting a concentration of a pollutant in the exhaust gas flow downstream of the first AT device. The AT system furthermore includes a deflector arranged between the injector and the sensor and configured to guide the flow of exhaust gas to the sensor to thereby concentrate the flow of exhaust gas at the sensor and direct the reductant spray away from the sensor to thereby minimize detection of the reductant by the sensor.

Abstract: An after-treatment (AT) system for an exhaust gas flow from an internal combustion engine includes first and second AT devices positioned in the exhaust gas flow. The AT system also includes an exhaust passage for carrying the flow of exhaust gas from the first AT device to the second AT device. The AT system additionally includes an injector configured to generate a reductant spray into the exhaust passage and a sensor positioned proximate the injector for detecting a concentration of a pollutant in the exhaust gas flow downstream of the first AT device. The AT system furthermore includes a deflector arranged between the injector and the sensor and configured to guide the flow of exhaust gas to the sensor to thereby concentrate the flow of exhaust gas at the sensor and direct the reductant spray away from the sensor to thereby minimize detection of the reductant by the sensor.

Abstract: In order to reduce erosion of an impeller due to liquid droplets in an incoming flow of gas, the impeller comprises converging-diverging bottlenecks; the incoming flow passes through the bottlenecks so that the speed of the gas at the inlet of the impeller first suddenly and substantially increases and then suddenly and substantially decreases; furthermore, the impeller is configured so that, internally after its inlet, the incoming flow is deviated gradually in the meridional plane.