Abstract: A device for actively controlling combustion instabilities and for decoking uel injectors comprises at least one detector for measuring pressure fluctuations in a combustion or afterburner chamber, means for processing the signal output by the detector and providing, in turn, a control voltage, and at least one piezoelectric device which is disposed in a hydraulic line including a fuel injector for the supply of fuel to the combustion or afterburner chamber and which is responsive to the control voltage to generate pulses in the flow of fuel from the outlet of the fuel injector.

Abstract: A redundant mass flow meter comprises a casing housing a main rotor and an ntermediate rotor which is freely rotatable and is disposed coaxially with a rotationally restricted turbine between the turbine and the casing, a first measuring system for measuring and controlling the position of the turbine relative to the intermediate rotor, and a second measuring system, independent of the first measuring system, for measuring and controlling the position of the intermediate rotor relative to the casing.