JET ENGINE PROPULSION Chapter 1 Compressor Operation

The correct name for a jet engine is a JET ENGINE PROPULSION The correct name for a jet engine is a GAS TURBINE ENGINE

Compressors THERE ARE TWO TYPES OF COMPRESSOR: AXIAL FLOW CENTRIFUGAL WE WILL LOOK AT THE AXIAL FLOW COMPRESSOR FIRST.

AXIAL COMPRESSOR OPERATION THE COMPRESSING ACTION CONSISTS OF TAKING A QUANTITY OF AIR AND FORCING IT INTO A SMALLER AND SMALLER SPACE THIS SQUARE REPRESENTS A QUANTITY OF AIR THIS SQUARE REPRESENTS THE SAME QUANTITY OF AIR BUT SQUEEZED INTO A SMALLER VOLUME LET’S SEE HOW THIS IS DONE

AXIAL COMPRESSOR OPERATION SQUEEZE PUSH BACK

AXIAL COMPRESSOR OPERATION SQUEEZE PUSH BACK

AXIAL COMPRESSOR OPERATION SQUEEZE PUSH BACK

AXIAL COMPRESSOR OPERATION SQUEEZE PUSH BACK

AXIAL COMPRESSOR OPERATION BIG AT FRONT SMALL AT REAR THIS IS WHY COMPRESSORS ARE SHAPED THE WAY THEY ARE

AXIAL COMPRESSOR OPERATION COMPRESSORS HAVE A SERIES OF ‘STAGES’ FRONT REAR COMPRESSORS HAVE A SERIES OF ‘STAGES’ EACH STAGE GIVES A SMALL PRESSURE RISE OVER THE PREVIOUS STAGE

AXIAL COMPRESSOR OPERATION FIRST STAGE ROTOR STATOR SECOND STAGE ROTOR STATOR THIRD STAGE ROTOR STATOR FOURTH STAGE ROTOR STATOR FIFTH STAGE ROTOR STATOR STATOR VANES ARE FIXED TO THE ENGINE CASING STATORS ROTOR BLADES ROTATE LIKE PROPELLOR BLADES ROTOR FRONT REAR FRONT REAR EACH STAGE CONSISTS OF A ‘ROTOR BLADE’ IN FRONT OF A ‘STATOR VANE’

AXIAL COMPRESSOR OPERATION COMPRESSOR ROTOR BLADES DO THE PUSHING BACK FRONT REAR COMPRESSOR ROTOR BLADES DO THE PUSHING BACK

AXIAL COMPRESSOR OPERATION COMPRESSOR STATORS VANES DO THE SQUEEZING FRONT REAR COMPRESSOR STATORS VANES DO THE SQUEEZING I.E. COMPRESSING THEY ALSO ENSURE THE AIRFLOW IS PRESENTED TO THE NEXT SET OF BLADES AT THE CORRECT ANGLE TO INCREASE EFFICIENCY.

AXIAL COMPRESSOR OPERATION

CENTRIFUGAL COMPRESSOR OPERATION A CENTRIFUGAL COMPRESSOR IS ONE WHICH TAKES THE AIR IN AT THE CENTRE OF A DISC AND DISCHARGES IT AT THE CIRCUMFERANCE. THE VOLUME OF THE IMPELLER IS REDUCED AS THE DIAMETER OF THE DISC INCREASES THEREFORE THE PRESSURE INCREASES.

CENTRIFUGAL COMPRESSOR OPERATION TO THE EXHAUST HERE. VOLUME DECREASES FROM THE INTAKE HERE. THUS PRODUCING A RISE IN PRESSURE I.E. COMPRESSION.

COMPRESSOR OPERATION WHENEVER AIR IS FORCED INTO A SMALLER SPACE TWO THINGS HAPPEN FIRST:- THE PRESSURE OF THE TRAPPED AIR INCREASES SECOND:- THE TEMPERATURE OF THE TRAPPED AIR ALSO INCREASES YOU CAN PROVE THESE TWO EFFECTS WITH A BICYCLE PUMP! IN A JET ENGINE COMPRESSOR, IT IS A CONSTANT FLOW OF AIR CONSTANTLY BEING COMPRESSED.

COMPRESSOR OPERATION