Zero-stage
Encyclopedia
Jet engine
s are often uprated by adding a zero-stage to the front of a compressor
. At a given core size, adding a stage to the front of the compressor not only increases the cycle overall pressure ratio, but increases the core mass flow.
This is demonstrated by the following relationship:
where:
core mass flow =
core size =
core total head pressure ratio =
inverse of core total head temperature ratio =
i.e. f(
)
core entry total pressure =
core entry total temperature =
On the other hand, adding a stage to the rear of the compressor increases overall pressure ratio, decreases core size, but has no effect on core flow. This option also needs a turbine with a significantly smaller flow capacity to drive the compressor.
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
s are often uprated by adding a zero-stage to the front of a compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
. At a given core size, adding a stage to the front of the compressor not only increases the cycle overall pressure ratio, but increases the core mass flow.
This is demonstrated by the following relationship:
where:
core mass flow =
core size =
core total head pressure ratio =
inverse of core total head temperature ratio =
i.e. f()core entry total pressure =
core entry total temperature =
On the other hand, adding a stage to the rear of the compressor increases overall pressure ratio, decreases core size, but has no effect on core flow. This option also needs a turbine with a significantly smaller flow capacity to drive the compressor.