Abstract: In a compressor stage including a movable bladed wheel having movable blades and a fixed bladed wheel having fixed blades, an air tapping circuit arrangement includes a movable wheel manifold designed to collect an air flow aspirated from the movable blades and a fixed wheel manifold designed to collect an air flow aspirated from the fixed blades. The movable wheel manifold is placed on the periphery of the compressor stage facing the movable wheel and the fixed wheel manifold is superposed on the movable wheel manifold.

Abstract: A compressor or fan is controlled to avoid stall, surge or flutter. The control system includes a look-up table from which is retrieved a margin-adjusted limiting value of a control parameter of the compressor, using inputs representing inlet guide vane angle (IGV), non-dimensional speed of the compressor (N/R?T), vehicle Mach number (Mn) and inlet geometry (IG). A variable stall, surge or flutter safety margin about a nominal limiting value of a control parameter is pre-established to reflect threats to the working, stall, flutter and surge lines, for example as a result of measurement inaccuracies, and from this the margin-adjusted limiting value is derived. An actual value of the control parameter is determined in real time, and the actual value is compared with the margin-adjusted limiting value. An output signal indicating stall, surge or flutter risk is generated if the actual value falls within the stall, surge or flutter safety margin.