A contact arm and a method for a disconnect switch, having a profile body and a contact element in electrical contact with the profile body to establish electrical contact with a contact counterpart. The profile body has a first diameter parallel to the contact element. The contact element has a concave surface with a radius of curvature and is arranged on a side directed away from the profile body. The radius of curvature is smaller than the radius of curvature of a circle segment having the first diameter of the profile body. The method includes a contact element of the contact arm establishing electrical and/or mechanical contact with a contact counterpart. A concave surface of the contact element which is directed towards the contact counterpart has a radius of curvature, which is smaller than the radius of curvature of a circle segment having the maximum diameter of the contact element.

Herein provided are methods and systems for controlling an engine having a variable geometry mechanism. A pressure ratio between a first pressure at an inlet of the engine and a predetermined reference pressure is determined. An output power for the engine is determined. The output power is adjusted based at least in part on the pressure ratio to obtain a corrected output power. A position control signal for a variable geometry mechanism of the engine is generated based on the corrected output power and the pressure ratio. The position control signal is output to a controller of the engine to control the variable geometry mechanism.

The present invention relates to a vacuum pump, in particular to a turbomolecular pump, having at least one pump stage and having a pressure determination unit for determining a pressure present at a suction side of the vacuum pump, said pump comprising a measurement device, with a measurement tap of the measurement device being provided in the region of the pump stage or downstream of the pump stage.

This invention relates to a turbocharger (210). More specifically, the invention relates to an axial-entry type turbocharger, where the exhaust gases are directed to meet the turbine wheel at least front-on, having a variable volume for controlling pressure, allowing for a substantially uniform pressure and uniform velocity to act simultaneously on and around the turbine wheel, while enabling the volume of the turbocharger to be adjusted under predetermined set pressure conditions. The turbocharge includes: a turbine housing defining a substantially axial primary flow duct, a primary turbine wheel (216) mounted along such primary flow duct (214), and a diverter (218) for diverting flow passing thereover into a primary annular flow path directed to impinge the primary turbine wheel (216). The turbine housing of the turbocharger defines a secondary flow duct (222) for directing some flow to: (i) impinge the primary turbine wheel (216); and/or (ii) bypass the primary turbine wheel (216). A secondary flow duct gate (223) controls flow through the secondary flow duct (222) and is movable between a closed position, wherein under low pressure conditions flow is restricted from flowing through the secondary flow duct (222), and an open position, wherein flow though the secondary flow duct (222) is enabled such that operative flow passes through both the primary and the secondary flow ducts (216, 222) under high pressure conditions. The turbocharger further includes at least one compressor coupled to the primary turbine wheel (216) via a primary transmission thereby to transmit drive from the primary turbine wheel (216) to the compressor.

Method for controlling a compressor comprising a last stage (40) and a compressor load controller (90), a set point outlet pressure corresponding to the consumer needed pressure, being given in the load controller (90) comprising the steps of: a—measuring the temperature at the inlet of the last stage (40), b—measuring the ratio between the outlet and inlet pressure of the last stage (40), c—computing a coefficient (Ψ) based on the value of the inlet temperature (Tin) and on the pressure ratio (Pout/Pin), d—if the coefficient (Ψ) is in a predetermined range, changing the set point outlet pressure by a new greater set point outlet pressure until the coefficient (Ψ) computed with the new set point outlet pressure goes out of the predetermined range, and e—adapting the pressure of the fluid coming out of the compressor in a pressure regulator (100) to the consumer needed pressure.

A surging precursor detecting device is a surge detecting device configured to detect a precursor of a surge of a compressor including a housing portion housing a blade including a rotary blade of an impeller and configured to compress a fluid supplied from an inlet piping portion and discharge the fluid to an outlet piping portion. The surging precursor detecting device includes an acquisition unit configured to acquire time series data of a state quantity having a correlation with internal pressure in at least one position of an inlet piping position, an outlet piping position, and an intermediate position between the inlet piping position and the outlet piping position, an analysis unit configured to perform a chaotic time series analysis on the time series data with the number of embedded dimensions being not less than three, and a detecting unit configured to detect a precursor of the surge.

There are described methods, systems, and assemblies for monitoring a bleed valve of a gas turbine engine. The method comprises determining a rate of change of a gas generator speed of the gas turbine engine; determining a rate of change of a parameter indicative of engine power of the gas turbine engine; comparing at least one ratio based on the rate of change of the gas generator speed and the rate of change of the parameter indicative of engine power to at least one range of values; detecting a modulation delay of the bleed valve when the at least one ratio is within the at least one range of values; and transmitting a signal indicative of the bleed valve malfunction in response to detecting the modulation delay.

A system and method of reducing engine induced aircraft cabin resonance includes sensing the core engine speed of a first turbofan gas turbine engine, and sensing the core engine speed of a second turbofan gas turbine engine. In a control system, the core engine speed of the first turbofan gas turbine engine and the core engine speed of the second turbofan gas turbine engine are processed to determine a core engine speed difference between the first and second turbofan gas turbine engines. The core engine speed difference is processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

A method to predict an onset of flow separation from a surface of an inner barrel of a nacelle is disclosed. In various embodiments, the method includes determining a static pressure distribution about the inner barrel surface of the nacelle; determining a mean static pressure value and a minimum static pressure value using the static pressure distribution; determining a separation indicator value using the mean static pressure value and the minimum static pressure value; and comparing the separation indicator value against a separation threshold value.

The disclosure includes controlling a pressure ratio for a compressing system, comprising introducing a quantity of liquid into an input stream to create a multiphase input stream, compressing the multiphase input stream with a centrifugal compressor to create a discharge stream, measuring a parameter of the discharge stream, wherein the discharge parameter corresponds to a pressure ratio for the centrifugal compressor, when the parameter exceeds a first predetermined point, increasing a pressure ratio of the centrifugal compressor by increasing the quantity of liquid introduced, and when the parameter exceeds a second predetermined point, decreasing the pressure ratio by decreasing the quantity of liquid introduced.