Performance Analysis of A Turboprop Engine P M V Subbarao Professor Mechanical Engineering Department Get More From Propeller……

Turboprop Engine VU

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.

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

Thrust Generated by propeller:

Jet Power of A Turboprop Jet Thrust:

Thrust Generated by A Turboprop

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

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

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

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

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

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

Optimum Design of Turboprop Optimum Turbine Pressure Ratio Compressor Pressure Ratio

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

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

Turboprop with Regeneration

High Fuel Economy due to Regeneration

Fitness of Engines for Flying Drag or Thrust Speed of Aircraft

Propulsion in Space Sky is the Limit

Travel Cycle of Modern Spacecrafts

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.