1.
15.4 COMPRESSORS
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2.
CENTRIFUGAL TYPE
SINGLE STAGE COMPRESSOR
TWO STAGE COMPRESSOR SINGLE STAGE DOUBLE ENTRY

3.
CENTRIFUGAL ASSY

4.
CENTRIFUGAL FEATURES
• ADVANTAGE
– Cheap and simple
– Not prone to FOD and icing
– Stable, no stall and surge
– Large rise in air pressure over distance
• DISADVANTAGE
– Limited compression ration 4:1
– Large frontal area
– Capacity is limit by impaler tip speed
– Easyly loss pressure due to severe change airflow direction

5.
AXIAL TYPE
SINGLE SPOOL TWIN SPOOL
TRIPLE SPOOL

6.
OPERATING PRINCIPLE
• Continuous compression
through each stage .
• Stage is defined as rotor and
stator
• Its form divergence duct
(continouse pressure rise) in
each stage

7.
CASCADE EFFECT
• Ability of the air to travel from low pressure
area to the high prassure area

8.
AXIAL ASSY

9.
AXIAL FEATURES
• ADVANTAGE
– High compression ratio
– Low fuel consumption
– Small frontal area and high volume of air
– Suit to high thrust
• DISADVANTAGE
– Complicated and expensive
– Poor acceleration
– Very severe to FOD
– Prone to stall and surge

10.
COMPONENT
• Rotor Blade :
– Airfoil section and twist to provide correct angle of attack (maintain
uniform airflow)
– Stager angle ( angle of incident of blade)
• Stator Vanes :
– Airfoil section and secure with casing
– Providing divergen blade spacing to effect sec stage compression
– Control direction airflow
• Fan type
– To produce thrust for turbofan engine and to pass air that not
required for combustion
– Engine more quiter and durable using fan
– High aspect ratio : thin and long blade (have clapper support)
– Low aspect ratio : wide chord and smaller blade

11.
ROTOR BLADE
Blade Attachment
Blade design

12.
STATOR VEIN
Variable stator
Fixed stator

13.
FAN
• FAN BALANCING
– Balance to prevent vibration and stress due to
high rotational speed
– Two type of balance:
• Single Plane or Static balance
• Two plane or dynamic balance

14.
MIX COMPRESSOR

15.
STALL AND SURGE
• Stall :
– Angle of attack of blade become to high or low due to airflow entry
condition.
– Indicate by increase in EGT, vibration and coughing noise
– Transition stall If slight vibration and poor acceleration occur shortly
– Hung stall cause all stage compressor stall and airflow will become
reverse flow (surge)
• Surge :
– Complete breakdown of airflow (all compressor stage stall)
– Due FOD, distored airfoil, bleed valve mailfunction cause the rear
compressor stage chock or exessive pressure ratio
– Indicate by abnormal engine noise, high EGT, vibration, flame emiting
in exhaust
– In extream condition, engine completely destroy

16.
AIRFLOW VARIATION

17.
AIRFLOW CONTROL
• Anti-surge device
– To prevent or reduce risk stall/surge and maintain
smooth airflow.
– By controlling the movement of airflow or
dumping the unstable airflow from compressor.
– Type :
• Variable intake guide vanes
• Variable stator vanes
• Compressor bleed valve

18.
ANTI-SURGE
Variable Inlet guide vanes control
Bleed Valves
Variable stator and actuator mechanism

19.
COMPRESSOR RATIO
• Calculated by dividing total pressure after last
stage of compresssion by total inlet pressure.
• Varies with RPM, intake temperature and
blade damage
• Overall pressure ratio for axial compressor is
30:1