Systems and methods for improved gas turbine engine performance are disclosed. The method can include receiving an error function for a wide range of fuels. The error function can provide lower heating value (LHV) corrections over the wide range of fuels. The method can include receiving gas turbine engine operation data for a first period of run time on the gas turbine from one or more sensors of the gas turbine engine. The engine operation data can include a performance data points. The method can include determining an optimum LHV based on the engine operation data for the first period of run time and the error function. The method can then include adjusting fuel consumption of the gas turbine engine based on the optimum LHV.

A control system for limiting a power turbine torque of a gas turbine engine is disclosed. In various embodiments, the control system includes an engine control module configured to output an effector command signal to a gas generator of the gas turbine engine; a power turbine governor module configured to output to the engine control module a power turbine torque request signal; and a power turbine torque limiter module configured to output to the power turbine governor module a power turbine speed rate signal to limit a power turbine speed overshoot of the gas turbine engine.

A system and method for detecting a shaft break in a turbofan gas turbine engine includes sensing fan rotational speed and sensing turbine engine rotational speed. A rate of change of rotational speed difference between the sensed fan rotational speed and the sensed turbine engine rotational speed is determined in a processor, and a determination that a shaft break has occurred is made in the processor based at least in part on the rate of change of the rotational speed difference.

A gas turbine engine defining a centerline and a circumferential direction, the gas turbine engine including: a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the turbomachine defining a working gas flowpath and a fan duct flowpath; a primary fan driven by the turbomachine defining a primary fan tip radius R.sub.1 and a primary fan hub radius R.sub.2; a secondary fan located downstream of the primary fan and driven by the turbomachine, at least a portion of an airflow from the primary fan configured to bypass the secondary fan, the secondary fan defining a secondary fan tip radius R.sub.3 and a secondary fan hub radius R.sub.4, wherein the secondary fan is configured to provide a fan duct airflow through the fan duct flowpath during operation to generate a fan duct thrust, wherein the fan duct thrust is equal to % Fn.sub.3S of a total engine thrust during operation of the gas turbine engine at a rated speed during standard day operating conditions; wherein a ratio of R.sub.1 to R.sub.3 equals $\sqrt{\left(\mathrm{EFP}\right)\frac{\left(1-Rq{R}_{\mathrm{Sec}.-{\mathrm{Fan}}^2}\right)}{\left(1-Rq{R}_{\mathrm{Prim}.-\mathrm{Fa}{n}^2}\right)}\left(\frac{1}{\%{\mathrm{Fn}}_{3S}}-1\right)};$

A fuel supply control device (8) is configured to control a fuel supply pump (3) on the basis of a front-rear differential pressure across a metering valve for a fuel supply amount, which is detected by a differential pressure gauge (7), using parallel flow passages of an orifice (6) and a pressurizing valve (5) as the metering valve. The fuel supply control device (8) includes a first control amount generation unit (8a) that is configured to generate a first control amount (S1) on the basis of the front-rear differential pressure, a second control amount generation unit (8b, 8c, and 8d) that is configured to generate a second control amount (S2) on the basis of the rotation speed of the fuel supply pump (3), a control amount selection unit (8f) that is configured to alternatively select the first control amount (S1) or the second control amount (S2) on the basis of the rotation speed, a subtracter (8g) that is configured to calculate a deviation of the output of the control amount selection unit (8f) from a control target value, and a control calculation unit (8h) that is configured to calculate an operation amount of the fuel supply pump (3) on the basis of the output of the subtractor (8g). The control amount selection unit (8f) is configured to select the first control amount (S1) in a case where the rotation speed is equal to or lower than a predetermined threshold and select the second control amount (S2) instead of the first control amount (S1) in a case where the rotation speed exceeds the threshold.

Systems and methods for improved gas turbine engine performance are disclosed. The method can include receiving an error function for a wide range of fuels. The error function can provide lower heating value (LHV) corrections over the wide range of fuels. The method can include receiving gas turbine engine operation data for a first period of run time on the gas turbine from one or more sensors of the gas turbine engine. The engine operation data can include a performance data points. The method can include determining an optimum LHV based on the engine operation data for the first period of run time and the error function. The method can then include adjusting fuel consumption of the gas turbine engine based on the optimum LHV.

The present invention relates to a rubbing position identification device for a rotating machine provided with a fixed part and a rotating part. This device is provided with an AE sensor, an axial vibration sensor and a rubbing position identification unit. In the case of rubbing occurring in the rotating machine, the rubbing position identification unit calculates the AE phase, which corresponds to the peak of an envelope determined on the base of change over time in the AE signal detected by the AE sensor, and the axial vibration phase, which corresponds to the high spot position of the rotating part specified on the basis of the change over time in the axial vibration signal detected by the axial vibration sensor, and, on the basis of the phase difference between these, identifies the circumferential-direction position of where rubbing has occurred in the rotating machine.

A method of predicting the condition of a compressor with respect to rotating stall is disclosed. The method comprises the steps of: i) comparing the difference between the largest and smallest values of a variable occurring during a time period with a difference threshold, the variable at any given time being dependent on the compressor exit pressure at that time, and ii) predicting either that the compressor is in rotating stall or that the compressor is not in rotating stall in dependence upon the result of the comparison.

A system and method for detecting a shaft break in a turbofan gas turbine engine includes sensing fan rotational speed and sensing turbine engine rotational speed. A rate of change of rotational speed difference between the sensed fan rotational speed and the sensed turbine engine rotational speed is determined in a processor, and a determination that a shaft break has occurred is made in the processor based at least in part on the rate of change of the rotational speed difference.

A motor controller of the present invention comprises units which obtain information indicative of a motor speed () and information indicative of motor torque (T), an air flow calculation section which calculates an air flow (Q) of a fan based on the motor speed () and the motor torque (T); and a speed command generation section which generates a speed command (*) of a motor such that the air flow (Q) coincides with the predetermined air flow command (Q*).