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Learn about the fundamentals of a turboprop engine for economic flying, fuel efficiency, and optimal performance. Understand the key aspects such as cruise speed, payload, range, and altitude requirements. Explore the theory behind turboprop engines and the philosophy of fuel economy for efficient flight transportation.
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Basics of A Turboprop Engine P M V Subbarao Professor Mechanical Engineering Department Enjoy the flying but pay for road travel ……
Economy Flying AN 12 : CRUISE SPEED : 520 km/h PAYLOAD : 18000 KG Range: 2400 km Maximum altitude: 7600 m
Requirements of Economic Flying • In recent years, interest in highly efficient flight transportation is renewed. • This has spurred investigation into very high bypass ratio fans. • Some economic optimization of turbofan cycle shows a bypass ratio of 100. • The weight of cowl and drag due to the cowl will have high penalty on total cost if bypass ratio is greater than 25. • This led to thinking of high bypass ratio open turbofan engines. • Turboprops.
4 5 6 7 1 2 1’ 3 Turboprop Engine : Just for Fuel Economy p04 =r0p,comp p0∞ = p05 T04= =t0p,comp T0∞ p02=p01= p03 = p0∞ T02=T01 = T03 = T0∞
JU 1 1 JD Actuator disc theory for Propeller pJD p p pJU VD p0JD VU p0D p0JU p0U
Power Consumed by Propeller The ideal shaft power can be found using the integral energy equation on the control volume:
Shaft Power Balance for Turboprop Law of Turboprop
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.