Overview of the relationship between fuel properties and engine performance Nader Rizk Rolls-Royce Indianapolis, IN ICAO Workshop, Aviation & Alternative Fuels Montreal, Canada 10-12 February 2009 2009 Rolls-Royce Corporation The information in this document is the property of Rolls-Royce Corporation and may not be copied or communicated to a third party, or used for any purpose other than that for which it is supplied without the express written consent of Rolls-Royce Corporation. This information is given in good faith based upon the latest information available to Rolls-Royce Corporation, no warranty or representation is given concerning such information, which must not be taken as establishing any contractual or other commitment binding upon Rolls-Royce Corporation or any of its subsidiary or associated companies. Page 1
Outline of Presentation OEMs joint test program Evaluation of fully synthetic aviation kerosene Full annular combustor test Material compatibility Full system evaluation Summary Concluding remarks 2
Alternative fuels requirements Offering longer term potential for drop-in fuels 3
Fuel approval process - Now in ASTM ballot Fuel Spec Properties ASTM D1655/ Def-Stan 91-91 Fit-for-Purpose Properties Seal Swell Lubricity Bulk Modulus Material Compatibility Additive Compatibility etc No Effect Component Test Fuel control Fuel pump Nozzle Turbine Combustor Rig Yes Component Test Required? No No Negative Impact No Anomalies Engine Test Required? Yes Negative Impact Negative Impact Reject & File Report Approval Incorporate into fuel spec Engine Test No Anomalies Negative Impact 4
OEMs engine and combustor test program To To assess effects of of SASOL fully synthetic jet jet fuel (FSJF) on on engine performance and operation, engine manufacturers (RR, P&W, GE and Honeywell), in in coordination with SwRI, conducted engine and combustor tests: Engine performance and endurance (P&W) Emissions (United Technologies -- P&W) Low temperature atomization (Honeywell) Cold ignition, altitude relight and lean blowout (Rolls-Royce and Honeywell) 5
Pratt & Whitney United Technologies tests JT9D engine endurance test for 500 test cycles Pre and post-test inspection involved: Fuel delivery system including control scheduling, O-rings, filters, etc. Fuel nozzles (position, flow, internal passages, etc.) Combustor liners (visual and video borescope) Emissions tests for an 80 o, four-nozzle arc sector of commercial combustor involved: ICAO LTO cycle and cruise: NOx, CO, and UHC CO2 and combustion efficiency Smoke number 6
Honeywell cold atomization tests Cold fuel atomization bench test for spray measurements Fuel atomizers tested included: Two representative pressure atomizers used in APUs of commercial and military transport in addition to regional aircraft Airblast atomizer used in several propulsion engines and some APUs Malvern particle analyzer determined spray droplet size distribution and Sauter mean diameter (SMD) Spray visualization and angle Fuel temperature down to level consistent with high altitude temperatures 7
Rolls-Royce cold-day ignition and altitude relight test Test conducted at high altitude test facility with an annular combustion system fully representative of a modern gas turbine Testing involved: Ignition under high altitude condition across full altitude relight envelope A ground ambient cold day condition ignition and extinction Extinction boundaries and blowout 8
Honeywell combustor lean stability test An annular combustor rig for a small turboshaft (helicopter) engine was used Lean blowout testing completed at representative flight and ground deceleration conditions Testing used FSJF, Jet A fuel, and weathered JP-5 fuel for comparisons FSJF and weathered JP-5 had flat distillation curves Lean blowout was detected by a rapid drop in combustor exit temperature 9
Rolls-Royce experimental evaluation of FSJF Objective: Assess impact of of Syntroleum Fischer-Tropsch fully synthetic aviation kerosene on on performance and material compatibility of of aircraft gas turbine engines by by evaluating: Combustion characteristics in in a production annular combustor and fuel nozzle assembly Effect on on oxidation of of turbine blade and vane alloys in in a cyclic oxidation rig rig Project sponsored by by Wright Patterson AFRL University of of Dayton participated in in material analysis 10
Distillation profiles of F-T and JP-8 fuels 300 Distillation Profiles 300 Distillation Profiles Temperature, C 250 200 150 100 50 0 JP-8 Spec Max JP-8 Tested Syntroleum F-T Tested 0 20 40 60 80 100 % Recovered Syntroleum F-T fully synthetic fuel exhibits fairly similar distillation profile to to that of of JP-8 tested under present study and both meet the JP-8 specifications SASOL F-T fuel has been approved for for use in in commercial aircraft but has distillation limitations to to ensure typical profile Temperature, C 250 200 150 100 50 0 0 20 40 60 80 100 % Recovered JP-8 Spec Max SASOL F-T Tested Syntroeum F-T Tested 11
Annular combustor rig F-T fuel trailer F-T fuel trailer Full annular combustor rig is used for testing AE 3007, AE 2100, and AE 1107 combustors, which have common parts with minor variations F-T and JP-8 tests used same combustor build The 100% SPK was held in a specially cleaned trailer and passed directly to the annular combustor 12
Full annular combustor test Stability boundaries Ignition and LBO characteristics Emissions at selected performance points Combustion efficiency map Gaseous emissions (NOx, CO, and UHC) Smoke Exhaust gas temperature profiles Radial temperature profiles Exit pattern factor Combustor liner temperatures Thermocouples measurement Thermal paint 13
Impact of key properties on performance 14
Impact of fuel on gaseous emissions 15
NOx emissions 30 NOx emissions, g/kg fuel 20 10 NOx Emissions for JP-8 and F-T Fuels JP-8 F-T 0 0 200 400 600 800 1000 BIT, F NOx emissions for FSJF are in general higher than for JP-8 Higher combustion heating value of FSJF results in favorable conditions for NOx formation 16
Liner thermocouple temperature 1500 Liner wall temperature. F 1300 1100 900 JP-8, Takeoff 100% F-T, Takeoff 1500 Liner wall temperature. F 1300 1100 900 JP-8, Altitude Cruise 100% F-T, Altitude Cruise 700 0 Front 2 4 6 8 10 12 Rear 14 Thermocouple (order by position) Thermocouple data data were were compared at at two two conditions having having similar similarbot: Moderate FAR FAR and and high high pressure representative of of T/O T/O High High FAR, FAR, low low pressure such such as as during during cruise-climb FSJF FSJF had had a higher higher heating heating value value resulting in in an an increase in in BOT BOT relative relative to to JP-8 JP-8 under under same same operating conditions Liner Liner temperatures are are fairly fairly similar similar at at most most locations with with some some advantage for for FSJF FSJF under under T/O T/O conditions Thermal paint paint results results did did not not reveal reveal differences in in localized hot hot or or cold cold spots spots 700 0 Front 2 4 6 8 10 12 Rear 14 Thermocouple (order by position) 17
Impact on other key performance parameters FSJF fuel exhibits similar stability and ignition characteristics at low and higher operating conditions to those for JP-8 fuel within experimental error CO and UHC emissions are similar for both fuels Full annular AE3007 combustor behaves like engine in producing extremely low smoke and remains nearly smoke free for both FSJF and JP-8 fuels No measurable differences are observed in pattern factor and radial profiles between JP-8 and FSJF fuels suggesting no adverse impact on turbine vane lives 18
Impact of F-T fuel on material Becon combustion rig A set of 12 alloy specimen rods and 2 thermocouple rods were mounted in a 600 RPM rotating carousel and cycled between hot and cold jets 19
Analysis of test specimens In order to determine whether FSJF fuel had same or different effect on several alloys used in engines as normal JP-8 fuel, test pins from Becon combustion rig test were analyzed by University of Dayton Samples were examined by two main methods: Visual analysis and optical metallography X-ray-fluorescence (XRF) and scanning electron microscopy (SEM) Photomicrographs of sections of 12 samples at both 100x and 400x magnifications showed that no significant difference was evident for any material in the two fuel environments Also, based on elemental intensity values, it would appear that the use of FSJF does not result in any significant compositional differences in material relative to compositions found for materials that were tested using JP-8 fuel 20
Airbus / Shell / Rolls-Royce A380 demo Flight evaluation of a 40% GTL kerosene fuel blended with conventional fuel Part of research program to understand renewable fuels and potential future applications: Aircraft - Airbus A380 MSN4 Engine - Trent 900 only one engine used the derived fuel Timing 1 Feb 2008 Data gathered throughout the test process reported and contributing to the capabilities and limitations of FT and also more recently renewable synthetic fuels 21
Rolls-Royce joins Air New Zealand, UOP and Boeing in renewable fuels study program Flight evaluation of a renewable bio fuel blended with kerosene fuel source Aircraft ANZ 747-400, Engine RB211-524GT, only one engine uses the fuel Timing 30 th Dec 2008 Fuel analysis shows fuel meets/exceeds current specification requirements 50:50 Blend - Jatropha derived SPK (Hydrogenated Vegetable Oil) and standard Jet A-1, therefore is drop-in Data gathered throughout the test process has contributed to understanding of the capabilities and limitations of renewable fuels Pre and Post engine hardware inspection is taking place 22
Summary OEMs joint test program, in coordination with SASOL and SwRI, provided significant engine and component performance data in support of FSJF assessment and approval Rolls-Royce assessed impact of Syntroleum fully synthetic aviation kerosene on performance and material compatibility of aircraft gas turbine though combustion testing in production annular combustor and Becon combustion rig Fuel properties impact almost all engine performance parameters and hot section material durability through their effects on fuel injection/spray evaporation processes and combustion characteristics Engine operability has been demonstrated for 2 different alternative fuels ICAO can play a significant role in promoting development of alternative fuels and incorporation in future regulation activities 23
Concluding remarks - The future Existing Rolls-Royce programs goals Meeting the challenge Supporting development of truly sustainable and viable alternative fuels for aviation: Whole life cycle evaluation Performance measurement and prediction Integration with engine development programs Creating the opportunities Creating new collaborative partners to evaluate and demonstrate alternative fuels e.g Qatar Consortium Contribution to European Union funded sustainable fuel programs- e.g, ALFA-BIRD, SWAFEA Engagement with key industry bodies e.g. CAAFI, Specification Owners (ASTM, Defence Standards), US Coordinating Research Council Improving test and evaluation capability, e.g, university collaborations Supporting the approval and rapid adoption of suitable alternative fuels 24
Thank you. Thank you. 25