Optimum Layout for a Turbofan Engine

1
Optimum Layout for a Turbofan Engine

• P M V Subbarao
• Professor
• Mechanical Engineering Department

An excellent Choice for Fighter Planes .
2
Mixed Flow Turbofan Engine
3
Ideal Mixer

• Ideal Mixer Constant Total Pressure Process.
• For a stable operation of the mixer, the inlet
  static pressures of core flow and fan flow must
  be equal.
• If they are not, back flow will occur in either
  the fan or core.

The stagnation pressure ratio across the fan
4
(No Transcript)
5
Condition for Efficient Mixing
6
Theory of Jet Propulsion Just Enough Work
The power inputs to the compressor fan The
power output of the turbine
7
(No Transcript)
8
Adiabatic mixing process
9
(No Transcript)
10
Mixed Flow Turbofan w/o AB
11
(No Transcript)
12
(No Transcript)
13
Generation of Thrust The Capacity
Propulsive Power or Thrust Power
Specific Thrust based on total jet flow S,
14
Thrust Specific Fuel Consumption TSFC
15
Aviation Appreciation
Propulsion Efficiency
16
Mixed Flow Fan Effect of Bypass Ratio
r0p,comp15 Mac0.75 t0,cc5.78
Non-dimensional TSFC
Non-dimensional Specific Thrust
17
Subsonic Operation Mixed Turbo Fan Mac0.75
Fan Pressure Ratio
Bypass Ratio
Compressor Pressure Ratio
18
Supersonic Operation Mixed Turbo Fan Mac2.0
Fan Pressure Ratio
2
Bypass Ratio
3
4
5
Compressor Pressure Ratio
19
Subsonic Operation Mixed Turbo Fan Mac0.75
Fan Pressure Ratio
5
TSFC
4
3
2
Compressor Pressure Ratio
20
Subsonic Operation Mixed Turbo Fan Mac0.75
Fan Pressure Ratio
2
3
Specific Thrust
4
5
Compressor Pressure Ratio
21
Supersonic Operation Mixed Turbo Fan Mac2.0
5
Fan Pressure Ratio
4
3
2
TSFC
Compressor Pressure Ratio
22
Supersonic Operation Mixed Turbo Fan Mac2.0
2
3
Specific Thrust
4
5
Compressor Pressure Ratio
23
Designs for Fuel Economy Subsonic Flight
5
Fan Pressure Ratio
TSFC
4
3
2
Compressor Pressure Ratio
Compressor Pressure Ratio
24
Designs for High Thrust Supersonic Flight
Mixed flow turbofan with After Burner
25
After burner temperatures are generally less than
after combustor temperature. T08 lt
T05 Generally the percentage of enhancement in
thrust is specified to determine temperature of
the gas after burner.
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
Generation of Thrust The Capacity
Propulsive Power or Thrust Power
Specific Thrust based on total jet flow S,
30
TF30 Pratt and Whitney Mixed Flow Turbofan Engine
The TF30-P-414 engine is a mixed flow, dual spool
afterburning low by pass turbofan designed and
manufactured by Pratt and Whitney Aircraft of
West Palm Beach, Florida. The engine
incorporates a nine stage low pressure compressor
including a three stage fan driven by a three
stage low pressure turbine and a 7 stage axial
flow high pressure compressor driven by a single
stage high pressure turbine.
31
SPECIFICATIONSTF30

• Development of TF30-P-414 was initiated in March
  1969.
• TF30-P-414A was placed in service in October
  1982.
• 929 TF30-P-414s were converted to P-414As with
  conversion kits conversion completed November
  1987.
• 269 P-414As were purchased.
• Max Design Pressure Ratio, SLS Fan 2.14 to 1
  Overall 19.8 to 1
• Bypass airflow ratio 0.878 to 1
• Max rated airflow 242.0 lbs/s

32
F110-GE-400 Mixed Flow Turbofan Engine
33
Details of F110-GE 400

• The F110-GE-400 engine is a mixed flow, dual
  spool afterburning low by pass turbofan designed
  and manufactured by General Electric Aircraft
  Engines in Lynn, Massachusetts.
• The engine is of modular construction, consisting
  of six engine modules, and an accessories
  gearbox.
• The engine incorporates a 3-stage fan driven by a
  two stage low pressure turbine and a 9-stage
  axial flow high pressure compressor driven by a
  single stage high pressure turbine.
• To moderate engine performance at various power
  levels the engine features a variable geometry
  system.
• The combustor is a through flow annular type.
• The hinged flap cam linked exhaust nozzle is
  hydraulically actuated.
• The engine mounted accessory gearbox provides the
  necessary extracted power needed to drive the
  accessories.
• The engine control system regulates speeds,
  temperature levels and fuel flow for afterburning
  and non after burning operation.
• The lubrication and ignition system are self
  contained on the engine.
• Development was initiated April 1984 and engine
  was placed in service in late 1986

34
SPECIFICATIONSF110-GE - 400

• Max Design Pressure Ratio, SLSFan3.2 to 1
• Overall 29.9 to 1
• Airflow Capacity Max rated airflow 270.0 lbs/s