Abstract: A system includes multiple blades coupled to a rotor, a stationary shroud disposed about the multiple blades, and a clearance between the stationary shroud and each blade end of the multiple blades, wherein the clearance is configured to enable over tip leakage flow. The system also includes a diffuser section that includes an outer wall defining an expanding flow path downstream from the multiple blades. The outer wall includes a first wall portion having a first angle relative to a rotational axis of the multiple blades, and the clearance is configured to enable an increase in the first angle by maintaining the boundary layer along the outer wall with the over tip leakage flow.

Abstract: An airfoil with a tip cover surface treatment for reducing leakage flows, minimizing tip vortex size and penetration into main flow that will improve turbine efficiency. The surface treatment for the airfoil tip covers includes a series of concave shapes, such as grooves or holes. These grooves and holes will cause the leakage flow into separate flow paths within the cavities and generate more resistance to leakage flows through the airfoil tip clearance, thereby reducing the leakage mass flow and weakening tip vortex and its interaction with turbine main flows. The material removed from the tip cover provides the additional benefit of reducing the weight of the tip cover, thereby enhancing blade reliability.

Abstract: A system includes multiple blades coupled to a rotor, a stationary shroud disposed about the multiple blades, and a clearance between the stationary shroud and each blade end of the multiple blades, wherein the clearance is configured to enable over tip leakage flow. The system also includes a diffuser section that includes an outer wall defining an expanding flow path downstream from the multiple blades. The outer wall includes a first wall portion having a first angle relative to a rotational axis of the multiple blades, and the clearance is configured to enable an increase in the first angle by maintaining the boundary layer along the outer wall with the over tip leakage flow.

Abstract: A transfer function between the inlet air-flow consumed by a Gas Turbine engine, and the engine parameters of speed, pressure ratio, and Inlet Guide Vane (IGV) angle is described. An active compressor Operating Limit Line (OLL) management strategy that leverages this improved flow measurement transfer function is also described. The improved flow measurement capability afforded by the transfer function permits a deterioration in flow rate caused by compressor fouling to be detected. Using the deterioration in flow rate as a proxy for compressor fouling, a degraded surge boundary associated with fouling can be predicted, using a transfer function between degradation of air-flow along operating line and degradation of surge line. In combination, the inventive improvements in flow measurement and operating line management afford added compressor surge protection across the operating range, while permitting the attainment of elevated pressure ratios associated with high thermodynamic efficiency and output.