assessing alternative fuels for helicopter operation alexiou, tsalavoutas, pons, aretakis,...

Assessing Alternative Fuels For Helicopter OperationAlexiou, Tsalavoutas, Pons, Aretakis, Roumeliotis, Mathioudakis

Click to edit Master title style

Assessing Alternative Fuels For Helicopter Operation

Alexiou, Tsalavoutas, Pons, Aretakis, Roumeliotis, Mathioudakis

Presented by

A. Alexiou

Laboratory of Thermal Turbomachines

National Technical University of Athens



Collaborative & Robust Engineering using Simulation Capability Enabling Next Design Optimisation

Environmentally Compatible Air Transport System

2

Acknowledgements



3

INTRODUCTION

MODELLING ASPECTS

o Mission Fuel Calculation

o Simulation Environment

o Helicopter-Engine Integrated Performance Model

o Alternative Fuels

CASE STUDY

o Engine Performance for Jet-A

o Helicopter Performance for Jet-A

o Effects of Alternative Fuels on Performance

SUMMARY & CONCLUSIONS

Contents



4

Introduction

Fuel Impact On Operating Costs

Year 2003 2005 2007 2009 2011

% of operating costs 14 22 28 26 30

Average price / barrel of crude ($) 28.8 54.5 73.0 62.0 110.0

Break even price / barrel ($) 23.4 51.8 82.2 55.4 112.5

Total fuel cost (bn $) 44 91 135 125 176

(http://www.iata.org/pressroom/facts_figures/fact_sheets/pages/fuel.aspx)



5

Introduction

(ACARE Beyond Vision 2020)

Global Man-Made CO2 Emissions


Click to edit Master title styleIntroduction

6

World Annual Traffic

(Airbus GMF 2010-2029)



7

Introduction

IATA VISION 2050Build a zero-emissions commercial aircraft within 50 years

Targets• Carbon neutral growth from 2020

• 1.5% average annual improvement of fuel efficiency

• 50% reduction of CO2 emissions by 2050 relative to 2005 levels

Four-Pillar Strategy• Technology (IATA target is for 10% of the fuel

used will be an alternative fuel by 2017)

• Operations

• Infrastructure

• Economic measures



8

Research is mainly focused on second or new generation bio-fuels (e.g. algae, jatropha and camelina).

Sustainable bio-fuels can reduce aviation’s net carbon contribution on a full life-cycle basis (60-85%).

Tests demonstrated that the use of bio-fuels as ‘drop-in’ fuels is technically sound and doesn’t require any major adaptation of the aircraft.

To date, aviation industry is cleared to use blends with up to 50% ‘synthetic’ kerosene derived from coal, gas or biomass and conventional jet fuel.



9

ObjectiveStudy the effect of alternative fuels on the performance of a medium utility helicopter

RequirementA helicopter mission analysis tool with the capability to use different fuels



10

INTRODUCTION

MODELLING ASPECTS




o Alternative Fuels

CASE STUDY





Contents



11

H/C new weight

6

Mission Fuel

7

H/C Specification• Take-Off weight• air bleed/power off-take

Air Intake lossesExhaust losses

Mission definitione.g. velocity, time for each segment

Oil & Gas SAR

Mission Fuel Calculation

ENGINE PERFORMANCE MODELFuel Flow

Rate 5

FUELMODEL

1

MISSION PROFILE

3H/C operating

conditions

H/C requirements(power, air cabin off

take, Nrotor)

2

H/C PERFORMANCE MODEL

4 -200

0

200

400

600

800

1000

1200

1400

1600

1800

0 10 20 30 40 50

Time (min)

Alt

itu

de

[m]



Object-Oriented Steady State Transient Mixed-Fidelity Multi-Disciplinary Distributed Multi-point Design Off-Design Test Analysis Diagnostics Sensitivity Optimisation Deck Generation

12

Simulation Platform

PROOSIS (PRopulsion Object-Oriented SImulation Software)



13

Simulation Platform

TURBO library of gas turbine components

Industry-accepted performance modelling techniques

Respects international standards in nomenclature, interface & OO programming



14

Simulation Platform

Total helicopter power Main rotor power

Induced Profile Fuselage Potential energy change

Tail rotor power Customer power extraction Gearbox power losses



IntegratedHelicopter-Engine

Component

15

Integrated Model

Engine Component

Helicopter Component (black box or PROOSIS model)



16

Alternative Fuels

FUEL H:C RATIO LHV (MJ/kg) DENSITY (kg/m3)

Jet-A 1.917 43.12 Ref. 801.0 RefSynjet (FT) 2.166 43.94 1.9% 762.4 -4.8%S8 (FT-GTL) 2.169 43.90 1.8% 756.0 -5.6%

Jatropha Algae (HRJ) 2.119 44.20 2.5% 748.0 -6.6%

Blend50% Jet-A + 50% Jatr.

2.017 43.70 1.34% 780.0 -2.6%

FT: Fischer-TropschHRJ: Hydrotreated Renewable JetGTL: Gas-to-Liquid

Low aromatics content Absence of natural anti-oxidants Low electrical conductivity Poor lubrication properties

Erroneous fuel metering Accelerated wear of fuel system O-rings/seals Fuel degradation in long-term storage High pressure fuel pump wear Increased fire hazard

PROOSIS TURBO library uses 3-D tables to calculate the caloric properties of the working fluid in

the engine model generated with the NASA CEA software (no dissociation)

Biodiesel (Soybean) 1.855 38.00 -11.9% 880.0 9.9%



17

INTRODUCTION

MODELLING ASPECTS




o Alternative Fuels

CASE STUDY





Contents



18

Engine Performance

PARAMETER MCP TOP OEI30Power Delivered [kW] 1056 1252 1437Torque Delivered [Nm] 1681 1992 2287Overall Pressure Ratio 11.6 12.6 13.3Power Turbine Inlet Temperature [K] 977 1034 1108Inlet Air Mass Flow Rate [kg/s] 4.6 4.8 4.94Gas Generator Speed [rpm] 38946 40205 41700Specific Fuel Consumption [kg/kWh] 0.280 0.271 0.269

Sea-level standard conditions



220 230 240 250 260 270 280 290 300 310 320 3300

200

400

600

800

1000

1200

01000200030004000500060007000

Tamb [K]

PW

SD

[k

W]

Altitude [m]

Maximum Continuous Power (MCP) Rating

Engine Performance

19


Click to edit Master title styleEngine Performance

20

500 700 900 1100 1300 1500 1700 1900 2100 2300 25000

100

200

300

400

500

600

700

MCPTOPOEI30

PWSD/(δ*θ1/2) (kW)

WF

/(δ

*θ1

/2)

(kg

/h)


Click to edit Master title styleEngine Performance

21

50 250 450 650 850 1050 1250 14500.25

0.35

0.45

0.55

0.65

0.75

0.85

0.95

PWSD (kW)

SF

C (

kg

/kW

.h)

MCP TOP OEI30


Click to edit Master title styleHelicopter Performance

22

PARAMETER SYMBOL VALUE UNITSMaximum Take-off Weight MTOW 7400 kg

Weight Empty WE 4105 kgFixed Useful Load FUL 200 kgFuel Capacity VFu 1.45 m3

Number of Engines Neng 2 -Number of Rotor Blades Nb 4 -Main Rotor Diameter D 15.2 mMain Rotor Blade Chord c 0.49 mMain Rotor Solidity σ 0.08 -Rotor Blade Tip Speed U 223 m/secRotor Speed NR 280 rpmEquivalent Flat Plate Area SCx 3.0 m2

Power Extraction Pex 10 kW



0 20 40 60 80 1000

500

1000

1500

2000

2500

5000 m4000 m3000 m2000 m1000 mSL

True Airspeed [m/s]

Po

we

r R

eq

uir

ed

[k

W]

MCP at SL

MCP at 5000 m

Helicopter Performance

23

Jet-A / MTOW / STD



24

0 10 20 30 40 50 60 70 80 90 1000

2

4

6

8

10

12

3500

4000

4500

5000

5500

6000

6500

7000

7500

Max Rate of Climb at 0 mMax Rate of Climb at 2000 mMax Altitude

True Airspeed [m/s]

Ma

x R

ate

of

Cli

mb

[m

/s]

Ma

x A

ltit

ud

e [

m]

Jet-A / MTOW / STD



25

0 10 20 30 40 50 60 70 80 90 1000

100

200

300

400

500

600

700

0

0.05

0.1

0.15

0.2

Specific Range

True Airspeed [m/s]

Sp

ecif

ic R

ang

e [m

/kg

]

Fu

el F

low

[kg

/s]

Vbe Vbr

SR = Vx / Wfuel

Jet-A / MTOW / SL / STD



26

0 200000 400000 600000 8000000

500

1000

1500

2000

2500

3000

3500

RANGE [m]

PA

YL

OA

D [

kg

]

Full Fuel Line

Jet-A


Click to edit Master title styleEffects of Alternative Fuels

27

Fixed PWSD (TOP for Jet-A)

Fixed XNH (TOP rating)



28

Synjet S8 (GTL) Jatropha/Algae (HRJ)

50% JetA+50% Jatr/Alg

Biodiesel (Soybean)

-4

-2

0

2

4

6

8

10

12

14

PWSD at MCP for JetAPWSD at TOP for JetAPWSD at OEI30 for JetA

WF

u %

Dif

fere

nc

e f

rom

Je

tA



0 10 20 30 40 50 600

500

1000

1500

2000

2500

Time [min]

Alt

itu

de

[m

]Effects of Alternative Fuels

29

Warm up at MCP [2’]

Take-Off [2’]

Climb at Vbe & Vz,max [2’]

Cruise at Vbr [40’]

Descent [4’]

Land [2’]



30

0 10 20 30 40 50 606600

6700

6800

6900

7000

7100

7200

7300

7400

7500JetA SynjetS8 (GTL) Jatropha Algea50% JetA + 50% JA Biodiesel

Time [min]

He

lic

op

ter

We

igh

t [k

g]

CRUISE

CLIMB

DESCENT

LAND

T/O



31

Synjet S8 (GTL) Jatropha Algea (HRJ)

50% JetA + 50% Jatr/Alg

Biodiesel (Soybean)

-4

-2

0

2

4

6

8

10

12

14

16

% C

ha

ng

e i

n M

iss

ion

Fu

el



Synjet S8 (GTL) Jatropha Algea (HRJ)

50% JetA + 50% Jatr/Alg

Biodiesel (Soybean)

-4

-2

0

2

4

6

8

10

12

14

16

Full TanksSame GTOW

% C

ha

ng

e i

n M

iss

ion

Fu

el

Effects of Alternative Fuels

32



33

4400 4900 5400 5900 6400 6900 7400530

550

570

590

610

630

650

670

690

710

730

Jet-A SynjetS8 (GTL) Jatropha Algea50% JetA +50% JA Biodiesel

Helicopter Weight [kg]

Sp

ec

ific

Ra

ng

e [

m/k

g]



500000 600000 7000000

500

1000

1500

2000

2500

JetA SynjetS8 (GTL) Jatropha Algea50% JetA - 50% JA Biodiesel

RANGE [m]

PA

YL

OA

D [

kg

]Effects of Alternative Fuels

34



35

INTRODUCTION

MODELLING ASPECTS




o Alternative Fuels

CASE STUDY





Contents


Click to edit Master title styleSummary & Conclusions

36

An integrated performance model of a helicopter and its turboshaft engine has been created in an object-oriented simulation environment to study the effects of alternative fuels on helicopter operation.

For the fuels considered in this study there are no significant effects on the engine cycle compared to Jet-A except for the fuel flow rate that changes according to the difference of each fuel’s lower heating value from the reference one.

Considering the helicopter in a mission, there is an added effect from the differences in density between the fuels that modifies the helicopter’s payload-range capability.

Based on the modelling assumptions, the blended fuel appears at the moment as the most suitable choice for the aspects considered in the presented analysis (e.g. taking into account its effects on engine cycle parameters and helicopter operational characteristics) but other parameters should also be taken into account to allow for a more complete assessment (e.g. economics of fuel production, emissions, etc.).


Click to edit Master title styleSummary & Conclusions

37

The method presented herein can be further extended by including models of other disciplines in the existing integrated model (e.g. economics, noise and particulate emissions, etc.). This would allow the required multi-disciplinary calculations (including design and optimisation) to be performed in a single simulation environment with all the associated benefits that such an approach offers (configuration management control, transparent exchange of information between modules, common modelling standards, flexible mathematical model handling, etc.).

Finally, by creating a library of specific aircrafts (rotary or fixed wing) and a corresponding one with engines (turboshafts, turbofans, etc.) one can perform such studies for various combinations of current and future aircraft-engine models.

Engine PerformanceSimulation

Environment

Engine Deck

Aircraft Performance& EmissionsNoise Module

ATLASAero-TooLs for Advanced SimulationsLibrary of Gas Turbine Engines



38

THANK YOU

Laboratory of Thermal Turbomachines

National Technical University of Athens



39


Click to edit Master title styleMission – engine performance

40


Click to edit Master title styleAlternative Fuels

41

0 10 20 30 40 50 60 70 80 90 1000

100

200

300

400

500

600

700

Jet-ASynjetS8 (GTL)Jatropha AlgeaBiodieselBlend

True Airspeed [m/s]

Sp

ec

ific

Ra

ng

e [

m/k

g]

Vbr



42

150 350 550 750 950 1150 1350 15500.25

0.35

0.45

0.55

0.65

0.75

800

900

1000

1100

1200

1300

1400

1500

1600

1700Global Performances - ISA/SL

PWSD (kW)

SF

C (

kg

/kW

.h)

T4

1 (

K)

assessing alternative fuels for helicopter operation alexiou, tsalavoutas, pons, aretakis,...

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