Analysis of Turbofan Engine

1
Analysis of Turbofan Engine

• P M V Subbarao
• Professor
• Mechanical Engineering Department

How to decide Cold Vs Hot ???
2
Ideal Turbofan Cycle
Total thrust is generated by both cold and hot
jets..
3
Analysis of fan
Analysis of Fan
Design Parameter Stagnation pressure ratio
4
Analysis of Compressor
Design Parameter Stagnation pressure ratio
5
(No Transcript)
6
Combined Gas Dynamic Thermodynamic SSSF model
for Turbine
7
(No Transcript)
8
Vigor of Hot Jet
9
Combined Gas Dynamic Thermodynamic SSSF model
for Hot Nozzle
10
Available life at the inlet to the nozzle will
decide the magnitude of T7h.
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
Combined Gas Dynamic Thermodynamic SSSF model
for Cold Nozzle
15
(No Transcript)
16
(No Transcript)
17
Generation of Thrust The Capacity
Propulsive Power or Thrust Power
Specific Thrust based on core flow S
Specific Thrust based on total flow S
18
Thrust Ratio
Ratio of specific thrust of core stream to
specific thrust of fan stream.
19
Thrust Specific Fuel Consumption TSFC
20
Aviation Appreciation
Propulsion Efficiency
21
Performance Analysis of Turbofan

• Operational Parameters Flight Mach number
  Ambient conditions.
• Design Variables Fan Pressure Ratio, Bypass
  Ratio, Compressor Pressure Ratio, Combustion
  Chamber Temperature Ratio.
• Fan Effects
• Fan Pressure Ratio
• Bypass Ratio.
• Fan Stream Thrust Vs Total Thrust.

22
Utility of of Fan Bypass Ratio
r0,p,fan2.5 r0,p,comp15 T0max1200K
Mac 0.75
23
Fan Effects . Fan Pressure Ratio Mac 0.75
r0,p,comp15.0 a4.0 T0max1200K
24
Effect of Flight Mach Number Compactness
Specific Thrust kN.s/kg
Mach Number
25
Effect of Flight Mach Number Fuel Economy
TSFC
Mach Number
26
Effect of Flight Mach Number Propulsion
Efficiency
Mach Number