This invention relates to a multi-stage rotor (10). More specifically, the invention relates to a multistage rotor (10) for the compressor stage of a machine that, through a concentric configuration of its innermost (12), outermost (24) and intermediary (16) blade sets co-operative with a reverse flow convoluting ducting arrangement, provides an axially compact, lighter and more easily maintainable compressor rotor for such machine. The multi-stage rotor (10) includes innermost (30), outermost (34) and intermediary (32) duct ports comprising a radial duct spans, as measured between respective diametrically inner and outer duct walls of the duct port, being greater than respective innermost (48), outermost (54) and intermediary (50, 52) radial blade spans of the respective blade sets rotatable at least partially within such duct port. In this manner, a gap is defined between: (i) the at least one diametrical ends of the radial rotating blades ending radially short of the respective radial duct span to form free ends of the blades; and (ii) a stationary part of the respective duct the free ends of the blades sweep neared to; for generating a friction wash between such free ends of the blades and the stationary part of the respective duct.

A nacelle for a gas turbine engine having a longitudinal centre line. The nacelle includes an air intake disposed at an upstream end of the nacelle. The air intake includes, in flow series, an intake lip, a throat and a diffuser. The diffuser further includes a diffuser angle (θ.sub.diff), indicating a degree of divergence of the diffuser relative to the longitudinal centre line. The diffuser angle (θ.sub.diff) is from about 0 degrees to about 12 degrees.

A nacelle for a gas turbine engine having a longitudinal centre line. The nacelle includes an air intake disposed at an upstream end of the nacelle. The air intake includes, in flow series, an intake lip, a throat and a diffuser. The diffuser further includes a diffuser angle (θ.sub.diff), indicating a degree of divergence of the diffuser relative to the longitudinal centre line. The diffuser angle (θ.sub.diff) is from about 0 degrees to about 12 degrees.

Methods, apparatus, systems and articles of manufacture for compact compressors are disclosed including a gas turbine engine defining an axial direction and a radial direction, the gas turbine engine including an axial flow compressor and a radial flow compressor, wherein the axial flow compressor is located axially forward of the radial flow compressor, a blade assembly including a splitter shroud to divide incoming air into axial air flow for the axial flow compressor and radial air flow for the radial flow compressor, the blade assembly rotating relative to the axial flow compressor and counter-rotating relative to the radial flow compressor, and wherein the blade assembly is located axially aft of the radial flow compressor.

A gas turbine engine for an aircraft includes an engine core including a turbine, compressor, and core shaft connecting turbine to compressor; a fan located upstream of the engine core and including a plurality of fan blades each having a leading and trailing edge. The turbine includes a lowest pressure turbine stage having a row of rotor blades, each rotor blades extending radially and having a leading and trailing edge. The engine has a fan tip axis that joins a radially outer tip of the leading edge of a fan blade and the radially outer tip of the trailing edge of a rotor blade of the lowest pressure stage. The fan tip axis lies in a longitudinal plane which contains a centreline of engine. A fan axis angle is defined as the angle between fan tip axis and centreline, and is in a range between 10 and 20 degrees.

A gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan, a nacelle including an inlet portion forward of the fan, a length of the inlet portion having a dimension L, and a dimensional relationship of L/D between 0.30 and 0.40.

A gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan, a nacelle including an inlet portion forward of the fan, a length of the inlet portion having a dimension L, and a dimensional relationship of L/D between 0.30 and 0.40.

A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

A gas turbine engine for an aircraft includes an engine core including an engine core, a turbine, a compressor, and a core shaft connecting the turbine to the compressor, the turbine comprising a lowest pressure rotor stage, the turbine having a turbine diameter at the lowest pressure rotor stage. A fan located upstream of the engine core, the fan comprising a plurality of fan blades extending from a hub, the hub and fan blades together defining a fan face having a fan face area and a fan tip radius. A ratio of the fan tip radius to the turbine diameter at the lowest pressure rotor stage is in the range from 1.2 to 2.0.