Systems and methods for predicting a surge event in a compressor of a turbomachine are provided. According to one embodiment of the disclosure, a system may include one or more computer processors associated with the turbomachine. The one or more computer processors may be operable to receive a plurality of performance parameters of the compressor and analyze the plurality of performance parameters to determine corrected performance values of the performance parameters. Based at least partially on the corrected performance values, a compressor efficiency may be determined. The processor may be further operable to standardize the compressor efficiency for a standard mode of operation, ascertain historical performance data associated with the standard mode of operation, and analyze the compressor efficiency based at least partially on the historical performance data. Based on the analysis of the compressor efficiency, a surge event may be selectively predicted.

A method of developing a suggested blend repair to an airfoil includes the steps of: (a) storing history with regard to a particular airfoil in a particular engine; (b) taking information with regard to new damage to the particular airfoil; (c) reaching an initial blend recommendation based upon step (b); (d) assessing whether the initial blend recommendation of step (c) would be appropriate to repair the new damage based upon a consideration of steps (a)-(c); and (e) reporting a final blend recommendation. An airfoil repair recommendation system is also disclosed.

A method and a system for synthesizing output power provided by an engine are provided. The engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the engine, a pressure of fluid at an exit of the compressor section, a temperature upstream of the exit of the compressor section, and a fuel flow rate to the engine are determined. A synthesized value of output power provided by the engine is determined based on a product of at least a first factor, a second factor, and a third factor, the first factor being a function of the pressure, the second factor being a function of the temperature, and the third factor being a function of the fuel flow rate. The synthesized value of output power provided by the engine is output.

A method and a system for synthesizing thrust from a turbofan engine are provided. The turbofan engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the turbofan engine, a pressure of fluid at an exit of the compressor section and a temperature of fluid at a location upstream of the exit of the compressor section are determined. A synthesized value of thrust from the turbofan engine is determined based on a product of at least a first factor and a second factor, the first factor being a function of the pressure and the second factor being a function of the temperature. The synthesized value of thrust from the turbofan engine is output.

A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Systems and methods for determining a pump flow (Q) of a pump are disclosed. A method for determining a pump flow (Q) of a pump includes calculating an inverse of a polynomial equation defining a DP-Q performance curve of a pump, where the inverse is a Q-DP polynomial equation defining the performance of the pump, receiving a pump head (DP) value from a pump head sensor associated with the pump, computing a pump flow based on the Q-DP polynomial equation, comparing the computed pump flow to a preset target flow rate, and automatically controlling a pump parameter of the pump such that the calculated flow rate becomes the preset target flow rate.

A gas turbine engine starting system including an electric start generator (ESG) free of temperature sensors and configured to provide torque to a gas turbine engine. A fuel metering module is configured to provide a quantity of fuel to the gas turbine engine, and an electronic control system (ECS). The ESG includes a plurality of subcomponents. The ECS is configured to predict a future temperature of the ESG, predict that at an ongoing start or an uninitiated start will be unsuccessful, and provide the prediction that at an ongoing start or an uninitiated start will be unsuccessful to an operator. The prediction of the future temperature of the ESG is based on a plurality of historical ESG thermal trending information and an input ambient temperature. The prediction that at an ongoing start or an uninitiated start will be unsuccessful is based on the future temperature of the ESG.

Controlling a switching element in accordance with a voltage output from a signal amplifying circuit enables adjusting a voltage to be received by a current calculation circuit. Even when a range of a air volume to be used is wide and a range of output of a DC motor is wide, or a current flowing through the DC motor has a wide range, a resistance value of a shunt resistor and an amplification factor of a signal amplifying circuit are not required to be reduced, and thus current detection accuracy of the DC motor can be improved.

There is described herein methods and systems for comparing an engine fluid signature of a first engine with engine fluid signatures of other engines of a same engine family. A delta signature is obtained via the comparison and delta signatures below a given threshold are considered similar. Historical data for each engine having a similar signature may then be used to determine the condition and the future states of the first engine.

According to an aspect, a method includes predicting, by a processor, a projected oil-wetted metal temperature in a lubrication system of a gas turbine engine at shutdown based on one or more thermal models prior to shutdown of the gas turbine engine. The processor determines a coking index based on the projected oil-wetted metal temperature and a coking limit threshold associated with one or more engine components. An oil coking mitigation action is triggered as a shutdown management event of the gas turbine engine based on the coking index.