A system includes a gas turbine system including a compressor, a combustor, a turbine, and an exhaust section. The system also includes multiple sensors coupled to components of the gas turbine system. The system further includes a controller communicatively coupled to the gas turbine system and the multiple sensors and configured to control operations of the gas turbine system, wherein the controller is configured to calculate a surrogate value for turbine exit Mach number based on the feedback from the multiple sensors and to utilize the surrogate value to derive a control action for the gas turbine system.

A variable vane apparatus includes: a case including two or more spaced-apart case pivots; a bellcrank pivotally connected to each case pivot, each of the bellcranks having an input arm and an output arm; a master rod including two or more segments pivotally connected to each other at rod pivots; and wherein the input arm of each of the bellcranks is pivotally connected to one of the rod pivots.

A variable vane apparatus includes: a case including two or more spaced-apart case pivots; a bellcrank pivotally connected to each case pivot, each of the bellcranks having an input arm and an output arm; a master rod including two or more segments pivotally connected to each other at rod pivots; and wherein the input arm of each of the bellcranks is pivotally connected to one of the rod pivots.

A gas turbine engine with a compressor supplying compressed air. A combustor receives the compressed air and fuel and generates a flow of combusted gas. A turbine receives a core flow of the combusted gas to rotate a turbine rotor. A turbine inlet nozzle directs the combusted gas to the turbine rotor. Vanes are disposed in the turbine inlet nozzle and rotate to vary a flow area through which the core flow passes. The vanes adjust a pressure ratio of the gas turbine engine to compensate for changing operational requirements of the gas turbine engine by rotating to positions matching the changing operational requirements.

A gas turbine engine with a compressor supplying compressed air. A combustor receives the compressed air and fuel and generates a flow of combusted gas. A turbine receives a core flow of the combusted gas to rotate a turbine rotor. A turbine inlet nozzle directs the combusted gas to the turbine rotor. Vanes are disposed in the turbine inlet nozzle and rotate to vary a flow area through which the core flow passes. The vanes adjust a pressure ratio of the gas turbine engine to compensate for changing operational requirements of the gas turbine engine by rotating to positions matching the changing operational requirements.

A system for energy conversion that includes a propulsion system, a fuel circuit, a combustion device, a turbine, and a load device. The fuel circuit is in fluid communication with a fuel tank and a fuel flow control device that separates a flow of fuel into a first portion and a second portion. The combustion device receives a flow of oxidizer and the second portion of fuel to generate combustion gases. The turbine receives the combustion gases from the combustion device via a fluid circuit. The load device is operably coupled to the turbine via a driveshaft and is configured to receive torque from the driveshaft.

A system for energy conversion that includes a propulsion system, a fuel circuit, a combustion device, a turbine, and a load device. The fuel circuit is in fluid communication with a fuel tank and a fuel flow control device that separates a flow of fuel into a first portion and a second portion. The combustion device receives a flow of oxidizer and the second portion of fuel to generate combustion gases. The turbine receives the combustion gases from the combustion device via a fluid circuit. The load device is operably coupled to the turbine via a driveshaft and is configured to receive torque from the driveshaft.

The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

A disclosed gas turbine engine includes a first fan section including a plurality of fan blades rotatable about an axis, a compressor in fluid communication with the first fan section, a combustor in fluid communication with the compressor and a first turbine section in fluid communication with the combustor. The first turbine section includes a low pressure turbine that drives the first fan section. A second fan section is supported between the first fan section and the compressor and is driven by a second turbine section disposed between the second fan section and the compressor for driving the second fan section.