Basic Comparison of Three Aircraft Concepts: Classic Jet Propulsion, Turbo-Electric Propulsion and Turbo-Hydraulic Propulsion

Aerospace Engineering - Master thesis

Master Thesis Defense

Supervisors:

Prof. Dr. Dieter Scholz Dr. Markus Trenker Clinton Rodrigo

29/10/19

Basic Comparison of Three Aircraft Concepts:

Classic Jet Propulsion, Turbo-Electric Propulsion

and Turbo-Hydraulic Propulsion

Contents

• Introduction

• Concepts

• Methodology

• Results

• Summary

• Conclusion

3

Introduction

Background

• Flightpath 2050 – reduction of carbon emissions by 70%

• Reducing the operating costs for aircraft operators

• Batteries are too heavy for passenger aircraft

• New technologies must not deviate from the crucial aircraft requirements

• Can the efficiency be increased with the technology available currently?

Fig 1: Various Electric propulsion system architectures (NAS 2016)

Introduction

Research Question

In light of today's propulsion options for passenger aircraft: What is the superior propulsion principle with respect to Direct

Operating Costs and environmental impact? Turbo-electric propulsion, turbo-hydraulic propulsion or the established reference, the turbofan engine?

Top Level Aircraft Requirements of A320 :

•

•

•

5

All Turbo-Electric/Hydraulic Propulsion

Fig 3: Turbo-hydraulic Engine Architecture

Better Power-to-Weight Ratio

Fig 2: Turbo-electric Engine Architecture (NAS 2016)

Better Efficiency

Fig 4: Turbo-Hydraulic Propulsion System

Power Generation Decoupled Thrust Generation

Partial Turbo-Electric/Hydraulic Propulsion

Fig 5: Working of Partial Turbo-Hydraulic/Electric System

• Power extracted from the shaft of the Turbofan engine

• Cruise thrust required ~ 20% Take-off thrust

• Electric/Hydraulic motors operated only during cruise

• New TSFC calculated with two methods

• Different hybridization levels were investigated

Fig 6: Partial Turbo-Hydraulic/Electric System

7

Methodology

Fig 7: Aircraft Design Methodology for All Turbo-Electric/Hydraulic Propulsion

All Turbo-Electric/Hydraulic Propulsion

TLAR of A320 Two Types of Gas Turbine Engine:

•

•

Methodology

Fig 8: Partial TE/TH Design Methodology

Partial Turbo-Electric/Hydraulic Propulsion

9

Preliminary Sizing Tool

Calculation Tool

• Getting Started

• Calculation Tool :

•

All Turbo-Electric/Hydraulic Partial Turbo-Electric/Hydraulic

•

•

•

•

•

•

Fig 9: The Calculation Tool

Preliminary Sizing Tool

Results

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Life Cycle Assessment

Operation

End-of-life

Wind tunnel testing

Flight test campaign

Material production Computer use

during design

Use of production facilities Production

Design &

Development

Landfill Reuse

Energy generation and consumption

at airports

Operation of ground handling vehicles

Kerosene production LTO-cycle

Cruise flight

• An Excel based Life Cycle Tool

• Developed in the AERO Group at HAW Hamburg.

• Given inputs are :

•

•

•

•

•

•

•

Results

Fig 12: Comparison of Direct Operating Costs and different

aircraft configurations Fig 13: Comparison of Trip Fuel Mass and different aircraft configurations Fig 14: Comparison of Life Cycle Assessment and different aircraft configurations

36.4 38.2

35.6 39.5

36.7 41.37

38.36 41.41

38.43

32.0 33.0 34.0 35.0 36.0 37.0 38.0 39.0 40.0 41.0 42.0

A320 TSTE2 TSTH2 TSTE4 TSTH4 TPTE2 TPTH2 TPTE4 TPTH4

Direct operating costs (M$)

Different Aircraft Configuration

8489.0008658.0 8369.4

9571.0 8707.8

10300.7 9173.3

9749.2 8729.0

0.000 2000.000 4000.000 6000.000 8000.000 10000.000 12000.000

A320 TSTE2 TSTH2TSTE4 TSTH4TPTE2TPTH2TPTE4TPTH4

Trip Fuel Mass (kg)

Different Aircraft Configuration

0.016 0.0173

0.0158 0.0192

0.0162 0.0204

0.0173 0.0197

0.0164

0 0.005 0.01 0.015 0.02 0.025

A320 TSTE2 TSTH2 TSTE4 TSTH4 TPTE2 TPTH2 TPTE4 TPTH4

LCA -Single Score

Different Aircraft Configuration

Turbo-Electric/Hydraulic Propulsion

13

Results

Fig 15: Number of engines against direct operating cost (M$)

Distributed Propulsion System

30 32 34 36 38 40 42 44 46

0 2 4 6 8 10 12 14

Direct operating costs (M$)

Number of Engines

Maintenance Costs Engine Mass Propeller Efficiency Operating Empty Mass

Results

Partial Turbo-Electric/Hydraulic Propulsion

116%

116%

136%

136%

115%

115%

148%

148%

133%

133%

144%

144%

243%

243%

232%

232%

0 1000 2000 3000 4000 5000 6000

TH-18%-Scholz TH-18%-Turbomatch TH-16%-Scholz TH-16%-Turbomatch TE-18%-Scholz TE-18%-Turbomatch TH-15%-Turbomatch TH-15%-Scholz TE-16%-Turbomatch TE-16%-Scholz TE-15%-Turbomatch TE-15%-Scholz TH-10%-Scholz TH-10%-Turbomatch TE-10%-Scholz TE-10%-Turbomatch

Engine mass (kg)

Aircraft configuration

0.0151 0.0152 0.0153 0.0154 0.0155 0.0156 0.0157 0.0158 0.0159 0.016 0.0161

A320 TSTH2 TH-18%-Scholz

LCA -Single Score

Aircraft Configuration

15

Results

Fig 17: Comparison of Direct Operating Costs and different

aircraft configurations Fig 18: Comparison of Trip Fuel Mass and different aircraft configurations Fig 19: Comparison of Life Cycle Assessment and different aircraft configurations

34.6 34.8 35 35.2 35.4 35.6 35.8 36 36.2 36.4 36.6

A320 TSTH2 TH-18%-Scholz

Direct Operating Costs (M$)

Aircraft Configuration

Turbo-Electric/Hydraulic Propulsion

7000 7200 7400 7600 7800 8000 8200 8400 8600

A320 TSTH2 TH-18%-Scholz

Fuel Mass (kg)

Aircraft Configuration

Summary

• A total of 30 aircraft configurations were studied

• Turbo-hydraulic propulsion system with 2 engines and turboshaft engine is the best among TE/TH propulsion.

• Turbo-hydraulic propulsion system producing 10% of thrust in cruise is the best configuration among Partial TE/TH propulsion.

22%

16%

14%

48%

Piping

Hydraulic pump Hydraulic Motor Gas Turbine Engine 28%

10%

28%

4%

30%

Electric Motor Power Electronics Electric Generator Distribution Cable Gas turbine Engine

17

Conclusion

• Turbo-hydraulic propulsion is superior to Turbo-electric propulsion

• Partial Turbo-Electric/Hydraulic Propulsion is superior to completely Turbo-Electric/Hydraulic concept

• Improvement in TE by using superconductive material can lead to benefits in mass and efficiency

• Distributed Propulsion System (DPS) might increase the direct operating costs

• Placement of engines can be further studied to increase the aerodynamic advantages

Thank you for your attention.

19

References

NAS 2016

NATIONAL ACADEMIES OF SCIENCES, ENGINEERING, AND MEDICINE: Commercial Aircraft Propulsion and Energy Systems Research – Reducing Global Carbon Emissions. Washington, DC : The National Academies Press, 2016. – URL: http://doi.org/10.17226/23490

JOHANNING 2017

JOHANNING, Andreas, 2017. Methodik zur Ökobilanzierung im Flugzeugvorentwurf. München : Verlag Dr. Hut, 2017. Available at:

https://www.fzt.haw-hamburg.de/pers/Scholz/Airport2030.html, archived as: http://d-nb.info/1133261876/34.