1. Performance Analysis of A Turboprop Engine
P M V Subbarao
Professor
Mechanical Engineering Department
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2. Turboprop Engine
VU

3. Propeller (Reaction) Power
Propeller work coefficient:
The work coefficient of a propeller depends on compressor pressure ratio and turbine pressure ratio.
The compressor pressure ratio and turbine pressure ratio are two independent design variables for a turboprop.

4. Power Generated by A Turboprop
The total propulsive power generated by an ideal turboprop is given by:
Define work coefficient
Total thrust generated by turboprop

5. Thrust Generated by propeller:

6. Jet Power of A Turboprop
Jet Thrust:

7. Thrust Generated by A Turboprop

8. Share of the Propeller : Work Coefficient
Turbine Pressure Ratio
0.10
0.167
0.25
0.333
Cprop
0.5
Compressor Pressure Ratio

9. Share of the Jet : Work Coefficient
Turbine Pressure Ratio
0.333
0.5
0.25
0.167
Cjet
0.10
Compressor Pressure Ratio

10. Total Work Coefficient
Turbine Pressure Ratio
0.10
0.167
0.25
0.333
Cturboprop
0.5
Compressor Pressure Ratio

11. Compactness of A Turboprop
Turbine Pressure Ratio
0.167
0.10
0.25
Specific Thrust :N.sec/kg
0.33
0.5
Compressor Pressure Ratio

12. Fuel Economy of A Turboprop
Turbine Pressure Ratio
0.5
0.33
TSFC : mg/N.s
0.25
0.167
0.10
Compressor Pressure Ratio

13. Efficiency of A Turbo Prop
Turbine Pressure Ratio
0.10
0.167
0.25 hp
0.333
Turbine Pressure Ratio
0.10
0.5
0.167 ho
0.25
0.333
0.5
Compressor Pressure Ratio

14. Optimum Design of Turboprop
Optimum Turbine Pressure Ratio
Compressor Pressure Ratio

15. Pratt & Whitney PW127G Turboprop
The result is class-leading fuel consumption and low green house emissions.

16. Specifications Type: Three spool, free shaft turboprop
Inlet: Scroll type
Compressor: Twin spool; 1 stage centrifugal LPC, 1 stage centrifugal HPC
Burner: Annular, reverse flow
Turbine: Three spool, single stage axial HPT, single stage axial LPC, 2 stage power turbine
Exhaust: Rear exit, axial flow jet-type outlet
Power Rating: 3,500 equivalent shaft horsepower at 1,200 rpm
Mechanical Horsepower Rating: 3,185 horsepower
Thrust Rating: 1750 lbt
Rated Torque Output: 13,939 lb/ft
Pressure Ratio: 14.5:1
Specific Fuel Consumption: .44 lb/shp/hr

17. Turboprop with Regeneration

18. High Fuel Economy due to Regeneration

19. Fitness of Engines for Flying
Drag or Thrust
Speed of Aircraft

20. Propulsion in Space
Sky is the Limit

21. Travel Cycle of Modern Spacecrafts

22. Requirements to REACH ORBIT
For a typical launch vehicle headed to an orbit, aerodynamic drag losses are in the order of 100 to 500 m/sec.
Gravitational losses are larger, generally ranging from 700 to 1200 m/sec depending on the shape of the trajectory to orbit.
By far the largest term is the equation for the space velocity increment.
The lowest altitude where a stable orbit can be maintained, is at an altitude of 185 km.
This requires an Orbital velocity approximately 7777 m/sec.
To reach this velocity from a Space Center, a rocket requires an ideal velocity increment of 9050 m/sec.
The velocity due to the rotation of the Earth is approximately 427 m/sec, assuming gravitational plus drag losses of 1700 m/sec.
A Hydrogen-Oxygen system with an effective average exhaust velocity (from sealevel to vacuum) of 4000 m/sec would require mri/ mrf = 9.7.