INTRODUCTIONINTRODUCTION

PISTON & JET ENGINESPISTON & JET ENGINES The last piston engines had The last piston engines had

better efficiency than the first better efficiency than the first jet engines used in aviation, jet engines used in aviation, yet jet engines have almost yet jet engines have almost replaced piston engines as replaced piston engines as aircraft power plant not only aircraft power plant not only in military aviation but also in in military aviation but also in civil aviation. civil aviation.

PISTON & JET ENGINESPISTON & JET ENGINES

The piston engines and the jet The piston engines and the jet engines used in aviation vastly engines used in aviation vastly differ in various constructional differ in various constructional aspects.aspects.

DDesign / performance esign / performance factorsfactors decide the suitability of decide the suitability of a particular type of aero-engine a particular type of aero-engine for selection in aircraft as the for selection in aircraft as the power plant. power plant.

PISTON & JET ENGINESPISTON & JET ENGINES Design criteriaDesign criteria

pay loadpay load frontal area and size of aircraftfrontal area and size of aircraft cost & speed of productioncost & speed of production ease of maintenanceease of maintenance metallurgical metallurgical requirementsrequirements working cycle working cycle aircraft speed aircraft speed operational flexibilityoperational flexibility landing / take-off runlanding / take-off run ease of controlease of control

PISTON & JET ENGINESPISTON & JET ENGINES Performance criteriaPerformance criteria

power-weight ratiopower-weight ratio flight envelope flight envelope thermal efficiencythermal efficiency fuel consumptionfuel consumption endurance of flight (range & endurance of flight (range &

duration) duration) RPMRPM engine vibrationengine vibration engine noiseengine noise

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