Core power

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Core power is a parameter used in aeroengine performance engineering to enable a comparison of the power capabilities of jet engine (e.g. turbofan) cores.

Although the alternative core size parameter is easier to compute, it only takes into account the basic flow size of the device, no account being taken of the impact of core supercharging or turbine rotor inlet temperature.

There are several definitions of core power in use, but the following definition is fairly popular:

The core of the engine is treated as a turbojet; so, for instance, in a simple 2-spool turbofan, the power requirements of the fan bypass section are ignored and LP turbine imagined to be only driving the inner part of the fan. Firstly, a calculation is undertaken to find the turbine exit conditions where sufficient power is being extracted from the turbine system to just drive the core compression system. Next, an ideal turbine expansion to atmospheric pressure is calculated, the core power being assumed equal to the estimated turbine shaft power.

In a turboshaft/turboprop , most of the core power is realised as shaft power, whilst in a turbojet the core power is converted into jet power. In a turbofan, some of the core power is transferred to the fan bypass section and then converted into jet power.