Gas turbine engine

Abstract

The disclosure relates to a gas turbine engine, and discloses an aircraft gas turbine engine (10) that comprises a low pressure compressor system comprising a low pressure compressor (15) coupled to alow pressure shaft (23), and a high pressure compressor (16) coupled to a high pressure shaft (24). An inner core casing (34) is provided radially inwardly of compressor blades (42) of the compressorsystem. A fan (13) is coupled to the low pressure shaft (24) via a reduction gearbox (14). The high pressure compressor (16) comprises an outer core casing arrangement provided radially outwardly ofcompressor blades of the high pressure compressor (16), the inner core casing (34) and outer core casing arrangement defining a core working gas flow path (B) therebetween; and the outer core casing arrangement comprises a first outer core casing (48) and a second outer core casing (50) spaced radially outward from the first outer core casing (48).

Description

technical field [0001] The present disclosure relates to geared aircraft gas turbine engines. Background technique [0002] Aircraft gas turbine engines typically include a gas turbine engine core and a core-driven fan enclosed in a fan nacelle. Air flows through the active fan and is split into two streams downstream - the bypass flow and the core flow. The ratio between the mass flow rate of air in the bypass flow and the air mass flow rate of the core flow is called the bypass ratio. At subsonic flight speeds, a large bypass ratio is required for high efficiency. [0003] Gas turbine engine efficiency can also be increased by increasing the overall pressure ratio (OPR). A high OPR results in high thermodynamic efficiency and thus extremely low fuel burn. High OPR can be achieved by increasing the number of compressor stages. [0004] However, a high OPR engine core (with a large number of compressor stages) and / or a high bypass ratio can result in a relatively long e...

AI Technical Summary

Problems solved by technology

Such cores may be prone to flexing in flight, which can cause rotor tip rubbing (potentially causing damage) and / or cause engine core blades and fan blades to require excessive tip clearance (leading to adverse effects on efficiency)

Increasing engine core stiffness through the use of additional struts can lead to engine weight penalties which again reduces the overall aircraft level reduction in fuel consumption provided by high bypass ratios and / or high OPR

Images