An gas turbine engine for an aircraft includes, in axial flow sequence, a compressor module, a combustor module, and a turbine module, together with a first electrical machine rotationally connected to the turbine module. The combustor module has a combustor volume V (cm.sup.3). In use, at a full power condition, the gas turbine engine has a maximum corrected core flow Q (m.sup.3/sec), and a ratio T of:

[00001]$T=\frac{\left(\mathrm{Maximum}\mathrm{Corrected}\mathrm{Core}\mathrm{Flow}=Q\right)}{\left(\mathrm{Combustor}\mathrm{volume}=V\right)}$

is in a range of between 450 and 2,500.

An gas turbine engine for an aircraft includes, in axial flow sequence, a compressor module, a combustor module, and a turbine module, together with a first electrical machine rotationally connected to the turbine module. The combustor module has a combustor volume V (cm.sup.3). In use, at a full power condition, the gas turbine engine has a maximum corrected core flow Q (m.sup.3/sec), and a ratio T of:

[00001]$T=\frac{\left(\mathrm{Maximum}\mathrm{Corrected}\mathrm{Core}\mathrm{Flow}=Q\right)}{\left(\mathrm{Combustor}\mathrm{volume}=V\right)}$

is in a range of between 450 and 2,500.

A gas turbine engine for an aircraft includes an engine core having a core length and comprising 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; and 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, wherein a ratio of the fan tip radius to the turbine diameter at the lowest pressure rotor stage is in a range from 1.2 to 2.0; and wherein the engine core length is in a range from 150 cm to 320 cm.

A gas turbine engine includes a propulsor, a compressor comprising a compressor rotor, and a turbine comprising a turbine rotor fixedly mechanically coupled to the compressor rotor. The propulsor and the compressor are arranged in axial flow series. The turbine rotor is radially outward of the compressor rotor, and the direction of fluid flow through the turbine is generally opposite the direction of gas flow through the propulsor and the compressor.

A gas turbine engine includes a rotatable first shaft, a first disk connected to the first shaft, a second disk connected to the first shaft, a combustor radially outward from the first disk and the second disk, and a heat exchanger connected to the combustor aft of the second disk. The first disk includes a row of low pressure compressor blades and a row of high pressure turbine blades connected to a radially outer end of the row of low pressure compressor blades. The second disk includes a row of high pressure compressor blades and a row of low pressure turbine blades connected to a radially outer end of the row of high pressure compressor blades.

A gas turbine engine has a compression system radius ratio defined as the ratio of the radius of the tip of a fan blade to the radius of the tip of the most downstream compressor blade in the range of from 5 to 9. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.

A gas turbine engine has a compression system radius ratio defined as the ratio of the radius of the tip of a fan blade to the radius of the tip of the most downstream compressor blade in the range of from 5 to 9. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.

A highly efficient gas turbine engine is a system wherein the fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

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.

A section for a gas turbine engine according to an example of the present disclosure includes, among other things, a rotor including a row of blades extending in a radial direction outwardly from a hub. The row of blades deliver flow to a bypass flow path, an intermediate flow path, and a core flow path. A first case surrounds the row of blades to establish the bypass flow path. A first flow splitter divides flow between the bypass flow path and a second duct. A row of guide vanes extends in the radial direction across the bypass flow path. A second flow splitter radially inboard of the first flow splitter divides flow from the second duct between the intermediate flow path and the core flow path. A bypass port interconnects the intermediate and bypass flow paths. A method of operation for a gas turbine engine is also disclosed.