Challenges of future aircraft propulsion

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CHALLENGES OF FUTURE AIRCRAFT PROPULSION: A REVIEW OF DISTRIBUTED

PROPULSION TECHNOLOGY AND ITSPOTENTIAL APPLICATION FOR THE ALL

ELECTRIC COMMERCIAL AIRCRAFT

GUIDE, SUBMITTED BY,

Er. JAN PUTHIYATH ANEESH A NAIR

ASSISTANT PROFESSOR ROLL NNO 9

M E DEPARTMENT S7 ME

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CONTENTS

• INTRODUCTION• PROBLEM DESCRIPTION• LITERATURE REVIEW AND THEORY• DISTRIBUTED PROPULSION SYSTEM• ELECTRICAL AIRCRAFT• CHALLENGES FOR DISTRIBUTED PROPULSION• APPLICATION• CONCLUSION• REFERENCE

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INTRODUCTION

• Introduction of distributed propulsion technology for future commercial air craft.

• Technological limitations and challenges of this specific technology are also considered in combination with an all electric aircraft.

• The technical lessons learned from aviation history are important venues for future technical progress.

• The aim is to make an assessment of aircraft distributed propulsion, with a mindset of environmental awareness.

• Modern electric aircraft are summarized.

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PROBLEM DESCRIPTION

• Need a system which reduces fuel consumption• Need a system with reduced noise pollution• Need a system with less emission• Need a small propulsion system• Non reliable• System should be easy maintainable• Propulsion system with short take off

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ADVANTAGES OF DISTRIBUTED PROPULSIONSYSTEM

• Reduction in fuel consumption by ingesting the thick boundary layer flow.• Span wise high lift providing is powered lift, boundary layer control, and/or

super circulation around the wing, all of which enable short takeoff capability.

• Better integration of the propulsion system with the airframe for reduction in noise to the surrounding community through air frame shielding.

• High production rates and easy replacement of engines or propulsor that are small and light.

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LITERATURE REVIEW AND THEORY

• In 1929, Dornier Do X , the world’s largest aircraft at the time, flew for the first time.

• In 1947. H-4 Hercules was the largest flying boat ever built and consisted of a single hull and eight radial engines.

• During the transition to the jet engine era, the Avro Type 706 Ashton Mk 3 aircraft , equipped with either five or six turbojet engines, initially flew in 1951.

• In 1953,The Boeing 747 used four turbofan engines on wing leading edges.

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DISTRIBUTED PROPULSION SYSTEM

• Distributed propulsion (DP) is a type of powered flight propulsion system for fixed-wing aircraft in which air flows and forces are distributed about a vessel.

• The concept of distributed propulsion is based on dividing up the thrust.

• Its goal is to increase performance in fuel efficiency, emissions, noise, field length, and handling performance as compared to the use of a single large engine, jet, or propeller.

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Hybrid wing body aircraft

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• Distributed propulsion technology refers to a propulsion concept in aviation where the means of propulsion consists of three or more propulsion units (engines /propulsors /thrusters/other propulsion units).

• The distributed propulsion categories can be divided into two major parts consisting of Leader and Follower arrangements.

• Leader arrangements refer to distributed propulsion concepts where all the propulsion units solely contribute to the propulsion thrust without driving a secondary propulsion unit(either entirely or partially), e.g, distributed engines.

• The Follower arrangement denotes a distributed propulsion concept where at least one propulsion unit is used as a secondary propulsion unit.

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ELECTRIC AIR CRAFT

• One of the distinct characteristics of the electric aircraft is that it employs electric motors instead of internal combustion engines.

• The electricity can be supplied to the electric motors using different methods such as fuel cells , batteries , solar cells , ultra capacitors , etc.

• The electric aircraft can broadly be divided into two main categories:

1. All Electric Aircraft

2. More Electric Aircraft

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ALL ELECTRIC AIRCRAFT

• Early days of the electric aircraft included a minimal electric part, which primarily consisted of the electrical power dependency for ignition purpose.

• Equipped with one or a small number of poly-phase synchronous generators in the speed range of 10,000 RPM to 20,000 RPM.

• Some advantages of this are

1. additional power for take-off

2. reduction of runway length

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Schematic view of ALL ELECTRIC AIR CRAFT

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THANK YOU

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MORE ELECTRIC AIRCRAFT

• The aim of the MEA concept for commercial future aircraft with large number of air passengers is to revisit the AEA concept, while maintaining the same number of air passengers and an increased gross weight.

• More electric technology is capable of reducing the empty weight of a typical airliner by around 10%.

• Supplying pneumatic power using air bleed from engine compressors is combined with the external gearbox that drives electrical generators.

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CHALLENGES FOR AN ALL ELECTRIC FUTURECOMMERCIAL AIRCRAFT EMPLOYING

DISTRIBUTED PROPULSION• If redundant APU's are needed for reliability purposes and selected components

are kept cooled and monitored to avoid electromagnetic interference.• The use of many electrical units and components, such as electric motors and

cables, imposes new weight penalties.• Protection of the aircraft system/data network and the limitation of its usage to

authorized personnel only.• One of the major challenges with a gradual transition from the MEA to• AEA is the power output for airborne generators and actuators. Mature

technology has been proven for 100–200kW generators, but achieving 1MW generators for airborne applications is a substantial challenge

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CONCLUSION

• Total aircraft propulsive power and weight are the two dominant factors most likely to impact a future commercial aircraft employing distributed propulsion technology.

• The expected increase of future MTOW and OWE imposes weight limitations on future propulsive unit.

• The average number of engines per aircraft considered in this study is four.• A more clearly defined distributed propulsion terminology is desirable to

permit engineers, scientists and researchers to discuss this emerging technology more efficiently.

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REFERENCES

• McDonald JJ. Howard Hughes and the Spruce goose. Blue Ridge Summit, PA: Tab Books Inc.; 1981. ISBN 0-8306-2320-5.

• Eden P, Moeng S. The complete encyclopedia of world aircraft. London, United Kingdom: Barnes & Noble Books/Amber Books Ltd.; 2002. ISBN: 0760734321.

• Grow HB. Aircraft wing with internal flow control propulsion. United States Patent Office 4,026,500; May 31, 1997.

• Harrison N, Anderson J, Fleming J, Ng Wing. Experimental investigation of active flow control of a boundary layer ingesting serpentine inlet diffuser. AIAA Paper 2007-843; 2007.