`1111111111111111111111111111111111111111111111111111111111111111
`3 1176 00138 6458
`
`/lj}5/l CR- /..j-Cf/ Lf 7-3
`
`NASA CR159473
`R79AEG478
`
`NASA-CR-159473
`19800006861
`
`\.
`
`Quiet Clean Short-Haul Experimental Engine
`(QCSEE)
`Final Report
`
`by
`
`William S. Willis
`GENERAL ELECTRIC COMPANY
`
`August 1979
`
`...
`
`Early Domestic Dissemination Legend
`of its possible commercial value, this dat8: • ...,t1:.l>¥f1fsned under
`contract NAS3-18021 is being
`wi thin the
`U.S.
`•.
`be
`U.S. in
`and used by the reCi'p-lo.e.nt wJ.th
`data will not be
`it be released outside
`domestic organization w..i..tlfout
`of General Electric
`Company. The
`contained in
`will be considered
`void after J.al'fl11G.y 1, 1980.
`any re-
`legend shall
`produc'
`of this da a l.n whole or in part.
`.
`Prepared For
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`NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
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`NASA-Lewis Research Center
`Contract NAS3-18021
`
`, I 11111111
`
`1111111111\\111111
`NF01l91
`
`GE-1011.001
`
`
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`GE-1011.002
`
`
`
`i . ovemment,
`
`12G
`
`1. RepOrt No.
`CRl59473
`4. Title and Subtitle
`Quiet Clean Short-haul Experimental Engine,(QCSEE)
`Final Report
`
`/1 . . . . ,
`•• 0.
`
`3. Recipient's Catalog No.
`5. Report Date
`August 1979
`
`I
`
`I 6. Performing Organization Code
`
`8. Performing Organization Report No.
`R79AEG478
`10. Work Unit No.
`
`7. Author(s)
`William S. Willis, Manager, QCSEE Systems
`9. Performing Organization Name and Address
`General Electric Company
`Aircraft Engine Group
`Cincinnati, Ohio 45215
`12. Sponsoring Agency Name and Address
`National Aeronautics and Space Administration
`Washington, D. C. 20546
`15. 'Supplementary Notes
`Program Final Report
`Project Manager: C.C. Ciepluch, QCSEE Project Office
`Technical Advisor: N.E. Samanich, NASA-Lewis Research Center, Cleveland, Ohio 44135
`16. Abstract
`The QCSEE Program included the design, fabrication, and testing of two experimental propulsion
`systems for powered-lift transport aircraft. The Under-the-Wing (UTW) engine was intended for
`installation in an externally blown-flap configuration and the Over-the-wing (OTW) engine for
`use in an upper-surface-b1owing aircraft., The UTW engine included variable-pitch composite fan
`blades, ,main reduction gear, composite fan frame and nacelle, and a digital control system.
`The OTW engine included a fixed-pitch fan, composite fan frame, boilerplate nacelle, and a
`full-authority digital control. Many acoustic, pollution, performance, and weight goals were
`demonstrated; all planned testing was satisfactorily completed prior to delivery of the engines
`to NASA for further testing.
`
`11. Contract or Grant No.
`NAS3-l802l
`13. Type of Report and Period Covered
`Contractor Report
`14. Sponsoring Agency Code
`
`"
`
`17. Key Words (Suggested by Author{s))
`Aircraft Propulsion
`Powered-Lift Systems
`Engine Acoustics
`Combustor Emissions
`Engine Testing
`19. Security Cassif. (ofthis report)
`Unclassified
`
`18. Distribution Statement
`
`EQxejgn Pis±$jJy'tiop
`
`20. Security Classif. (of this page)
`21. No. of Pages
`Unclassified
`293
`* For sale by the National Technical Information Service, Springfield, Virginia 22151
`
`22. Price·
`
`NASA·C·l68 (Rev. 6-71)
`
`j(j f'1) - /,j-/
`
`$
`(J
`
`GE-1011.003
`
`
`
`GE-1011.004
`
`
`
`Section
`1.0
`2.0
`
`3.0
`
`TABLE OF CONTENTS
`
`SUMMARY
`INTRODUCTION
`2.1 Background
`2.2 Design Approach
`ENGINE DESIGN
`3.1 Overall Engine Description
`3.2 Fan Aerodynamics
`3.2.1 UTW Fan Aerodynamics
`3.2.2 OTW Fan Aerodynamics
`3.3 Composite Fan Blades
`Design Requirement$
`3.3.1
`Design Description
`3.3.2
`FOD Resistance
`3.3.3
`3.4 Variable-pitch-Actuation System
`Cam/Harmonic Variable-pitch System
`3.4.1
`3.4.2
`Ball Spline System
`3.5 Main Reduction Gear
`3.5.1
`Design Requirements
`3.5.2
`Design Approach
`Design Summary
`3.5.3
`Hardware Fabrication
`3.5.4
`3.5.5
`Rig Testing
`,Composite Fan Frame
`3.6.1
`Design Requirements
`3.6.2
`Structural Description
`Fabrication
`3.6.3
`Testing
`3.6.4
`3.7 Composite Nacelle
`3.7.1
`Inlet
`3.7.2 Outer Cowl and Fan Nozzle
`3.7.3
`Inner Cowl
`
`Page
`1
`
`6
`6
`6
`14
`14
`18
`18
`31
`37
`37
`43
`51
`51
`51
`66
`70
`70
`74
`78
`80
`80
`82
`86
`86
`94
`100
`100
`100
`110
`117
`
`iii
`
`GE-1011.005
`
`
`
`TABLE OF CONTENTS (Continued)
`
`Section
`
`Action
`
`3.8 Digital Control System
`UTW Design Requirements
`3.8.1
`UTW System Description
`3.8.2
`UTW Operating Characteristics
`3.8.3
`UTW Automatic Safety Limits
`3.8.4
`UTW Transient Response
`3.8.5
`OTW Design Requirements
`3.8.6
`OTW Control System Description
`3.8.7
`OTW Operating Characteristics
`3.8.8
`OTW Transient Thrust Response
`3.8.9
`Failure Indication and Corrective
`3.8.10
`3.9 Low-Emissions Combustor
`Design Requirements
`3.9.1
`Approach
`3.9.2
`Development Program
`3.9.3
`Test Results
`3.9.4
`3.10 Acoustic Design
`3.10.1 Engine Acoustic Features
`3.10.2 Fan Inlet Design
`3.10.3 Fan Exhaust Design
`3.10.4 Core Suppressor Design
`3.10.5 QCSEE UTW System Noise Predictions
`3.10.6 QCSEE OTW System Noise Predictions
`ENGINE TEST RESULTS
`4.1 Overall Engine Performance
`4.1.1 UTW Performance Test
`4.1.2 OTW Performance Test
`4.2 Fan Aerodynamic Performance
`4.2.1 UTW Fan
`4.2.2 OTW Fan
`4.2.3 Conclusions
`4.3 Mechanical Performance
`Composite Fan Blades
`4.3.1
`Variable-Pitch Actuation Systems
`4.3.2
`Main Reduction Gear
`4.3.3
`Composite Frame
`4.3.4
`Composite Nacelle
`4.3.5
`
`iv
`
`4.0
`
`Page
`117
`123
`124
`128
`130
`133
`133
`135
`135
`138
`138
`141
`141
`144
`149
`149
`155
`164
`167
`168
`176
`183
`187
`194
`194
`194
`205
`205
`205
`217
`217
`221
`221
`221
`223
`223
`225
`
`GE-1011.006
`
`
`
`TABLE OF CONTENTS (Concluded)
`
`Section
`
`5.0
`
`6.0
`7.0
`
`4.4 Control System Test Results
`UTW Engine
`4.4.1
`OTW Engine
`4.4.2
`4.5 Acoustic Test Results
`Test Configuration and Measurements
`4.5.1
`UN Results
`4.5.2
`OTW Results
`4.5.3
`Summary
`4.5.4
`4.6 Measured Propulsion System Weight
`UTW System
`4.6.1
`OTW System
`4.6.2
`4.7 Thrust-to-Weight Ratio Assessment
`CONCLUS IONS
`Engine Performance
`5.1
`Fan Performance
`5.2
`Composite Fan Blades
`5.3
`Variable-pitch Systems
`5.4
`Main Reduction Gear
`5.5
`Composite Frame
`5.6
`Composite Nacelle
`5.7
`Digital Control
`5.8
`Low-Emission Combustor
`5.9
`Acoustics
`5.10
`Weight
`5.11
`RECOMMENDA TIONS
`RELATED REPORTS
`
`Page
`225
`225
`228
`234
`237
`237
`256
`272
`275
`277
`277
`282
`283
`283
`283
`284
`284
`284
`285
`285
`285
`286
`286
`286
`288
`290
`
`v
`
`GE-1011.007
`
`
`
`LIST OF ILLUSTRATIONS
`
`Page
`3
`
`4
`
`7
`
`UTW QCSEE.
`OTW QCSEE.
`Effect of Jet/Flap Noise on Fan Pressure Ratio Selection.
`UTW Propulsion System.
`OTW Propulsion System.
`Baseline UTW Aircraft.
`Baseline OTW Aircraft.
`UTW Engine Cross Section.
`OTW Engine Cross Section.
`UTW Fan Cross Section.
`UTW Variable-Pitch Fan Design Map.
`UTW Variable-Pitch Fan Design Map.
`UTW Fan Rotor.
`UTW Fan Bypass OGV Design.
`UTW Fan Rotor Blade; Forward-Mode Operation.
`UTW Fan Rotor Blade; Reverse Through Flat pitch Operation.
`UTW Fan Rotor Blade; Reverse Through Stall Operation.
`29
`UTW Scale-Model Fan.
`30
`UTW Fan, Scale-Model, Bypass Performance.
`32
`UTW Fan Takeoff Operation Scaled from Model Data.
`33
`UTW Fan, Scale-Model, Hub Performance at 100% Corrected Speed. 34
`UTW Fan, Scale-Model, Reverse-Mode Performance.
`OTW Fan Cross Section.
`
`9
`11
`12
`13
`15
`17
`19
`21
`22
`24
`26
`27
`
`28
`
`35
`
`36
`
`Figure
`l.
`2.
`3.
`4.
`5.
`6.
`7.
`8.
`9.
`10.
`ll.
`12.
`13.
`14.
`15.
`16.
`17.
`18.
`19.
`20.
`21.
`22.
`23.
`
`vi
`
`GE-1011.008
`
`
`
`Figure
`24.
`25.
`26.
`27.
`28.
`29.
`30.
`31.
`32.
`33.
`34.
`35.
`36.
`37.
`38.
`39.
`40.
`4l.
`42.
`43.
`44.
`45.
`46.
`
`LIST OF ILLUSTRATIONS (Continued)
`
`OTW Fan Design Map.
`OTW Fan Rotor Design Total-Pressure Ratio Radial Profile.
`OTW Fan Rotor.
`Fan Rotors.
`UTW Engine Composite Fan Blade Features.
`Composite Fan Blade Ply Assembly.
`Composite Fan Blade Platform Construction.
`Composite Fan Blade Campbell Diagram.
`Composite Fan Blade Goodman Diagram.
`Composite Fan Blade Whirligig Impact-Test Facility.
`Bird-Impact-Test Results.·
`UTW Fan Blade Twisting (Moment) Loads.
`Block Diagram of Pitch-Change Mechanism.
`Schematic of Pitch-Change Mechanism.
`Cam/Harmonic Variable-pitch Actuator System.
`Harmonic Drive.
`Harmonic-Drive Components.
`Harmonic-Drive Cam.
`Actuator in Whirl Rig.
`GE Ball Spline Actuator System.
`Pitch-Change Mechanism.
`Ball Spline Actuation System.
`Pitch-Actuator Components.
`
`vii
`
`Page
`38
`40
`41
`42
`45
`47
`48
`49
`50
`53
`54
`56
`
`.57
`
`58
`
`60
`61
`63
`64
`65
`67
`68
`69
`
`71
`
`GE-1011.009
`
`
`
`Figure
`47.
`
`49.
`50.
`5l.
`52.
`53.
`54.
`55.
`56.
`57.
`58.
`59.
`60.
`61.
`62.
`63.
`64.
`65.
`66.
`67.
`68.
`69.
`
`LIST OF ILLUSTRATIONS (Continued)
`
`Whirl-Rig Test Setup.
`QCSEE UTW Main Reduction Gear.
`YT49-W-l Reduction Gear.
`Reduc t ion Gear.
`Main Reduction Gear Test Rig Schematic.
`Main Reduction Gear Test Rig, Slave Unit (Drive) End.
`QCSEE Fan Frame.
`QCSEE Integrated Fan Frame.
`QCSEE Composite Frame.
`Analytical Model Comparison.
`Spoke Subcomponent Test.
`Assembly of Aft Wheel.
`QCSEE Aft Wheel.
`Assembled Wheel Structure.
`Laser Drilling of Acoustic Holes.
`Fan Casing Fabrication.
`Fan Casing Subassembly.
`Assembling Fan Case to Frame.
`QCSEE Fan Frame.
`QCSEE Fan Frame.
`Static Test Setup.
`UTW Composite Nacelle.
`Composite Applications.
`
`viii
`
`Page
`72
`73
`75
`77
`81
`83
`85
`87
`90
`93
`96
`97
`98
`99
`101
`102
`103
`104
`105
`106
`107
`108
`109
`
`GE-1011.010
`
`
`
`,
`LIST OF ILLUSTRATIONS (Continued)
`
`Inlet-to-Frame Attachment Tkst.
`Differential Pressures.
`Outer Cowl Fabrication.
`Completed Outer Cowl.
`Fan Nozzle.
`Outer Cowl Static Load Test.
`Inner Core Cowl Estimated Temperatures (Heat Shield
`Installed) •
`Completed Core Cowl.
`Core Cowl Interior View.
`UTW Control System Schematic.
`UTW QCSEE Digital Control.
`UTW Control System Sensors.
`UTW Fan Nozzle Control Characteristics.
`UTW Fan pitch Control Characteristics;
`UTW Predicted Transient Response.
`OTW Control System Schematic.
`OTW Control System Sensors.
`OTW Acceleration Fuel Schedule.
`OTW Predicted Transient Response.
`OTW Failure Indication and Corrective Action.
`FICA Dynamic Simulation Results; Power Chop to 62% and Power
`Burst to 100%.
`QCSEE Single-Annular, Low-Emissions Combustor.
`
`Page
`112
`113
`114
`115
`116
`118
`
`119
`
`121
`122
`125
`127
`129
`131
`132
`134
`136
`137
`139
`140
`142
`
`143
`145
`
`Figure
`70.
`71.
`72.
`73.
`74.
`75.
`76.
`
`77.
`78.
`79.
`80.
`81.
`82.
`83.
`84.
`85.
`86.
`87.
`88.
`89.
`90.
`
`91.
`
`ix
`
`GE-1011.011
`
`
`
`Figure
`92.
`93.
`94.
`95.
`96.
`97.
`98.
`99.
`100.
`101.
`102.
`103.
`104.
`105.
`106.
`107.
`108.
`109.
`
`1l0.
`
`lll.
`112.
`113.
`
`LIST OF ILLUSTRATIONS (Continued)
`
`QCSEE Double-Annular Dome Combustor.
`NASA QCSEE Double-Annular Combustor.
`Double-Annular Test Sector.
`Double-Annular Sector Prior to Assembly.
`Double-Annular Combustor Test Rig.
`Key Development-Test Results.
`Key Emissions-Test Results.
`Swirl Cups.
`Final Configuration.
`Altitude Ignition Results.
`QCSEE Acoustic Objectives.
`Aircraft Noise Trends.
`Unsuppressed Fan Exhaust Spectra.
`UTW Engine Acoustic Features.
`OTW Engine Acoustic Features.
`QCSEE Inlet-Noise-Reduction Concepts.
`UTW QCSEE in Anechoic Chamber.
`High Throat Mach No. Inlet Suppression, 50.8 cm (20 in.)
`Simulator Test.
`Reverse-Thrust Suppression, 50.8 cm (20 in.) Simulator
`Test.
`Inlet Acoustic Configurations.
`Inlet Acoustic Treatment.
`Exhaust-Radiated-Noise Model.
`
`x
`
`Page
`147
`148
`150
`151
`152
`153
`154
`156
`157
`159
`160
`162
`163
`165
`166
`168
`169
`
`171
`
`172
`173
`174
`175
`
`GE-1011.012
`
`
`
`LIST OF ILLUSTRATIONS (Continued)
`
`Effect of Vane Number on Second-Harmonic SPL.
`Summation of Rotor-Turbulence and Rotor/Stator Noise.
`Scale-Model Suppression Test Results.
`Fan Exhaust Treatment Configuration.
`Single-Degree-of-Freedom Exhaust Acoustic Treatment.
`Predicted UTW Fan Exhaust Suppression.,
`Core Stacked-Treatment Supression.
`QCSEE Core Exhaust Nozzle.
`Hot Duct Model Test Data.
`UTW Takeoff Noise Predictions.
`UTW Approach Noise Predictions.
`UTW Reverse-Thrust Noise Predictions.
`OTW Takeoff Noise Predictions.
`OTW Approach Noise Predictions.
`OTW Reverse-Thrust Noise Predictions.
`UTW Engine with Bellmouth Inlet.
`UTW Experimental Propulsion System Test Installation.
`UTW Measured Thrust, Bellmouth Inlet.
`UTW Measured Thrust, Bellmouth Inlet, 97% Corrected
`Fan Speed.
`UTW Thrust/SFC,
`UTW Reverse-Thrust Test.
`UTW Reverse Thrust.
`
`Inlet.
`
`Figure
`114.
`115.
`116.
`117.
`118.
`119.
`120.
`121.
`122.
`123.
`124.
`125.
`126.
`127.
`128.
`129.
`130.
`131.
`132.
`
`133.
`134.
`135.
`
`xi
`
`,Page
`177
`178
`
`179
`
`180
`
`181
`182
`184
`
`185
`186
`188
`189
`
`190
`
`191
`192
`193
`
`196
`
`197
`
`198
`
`200
`
`201
`202
`203
`
`GE-1011.013
`
`
`
`Figure
`136.
`137.
`138.
`l39.
`140.
`141.
`142.
`143.
`144.
`145.
`146.
`147.
`148.
`149.
`150.
`151.
`152.
`153.
`154.
`155.
`156.
`157.
`158.
`
`LIST OF ILLUSTRATIONS
`
`OTW Experimental Propulsion System Installation.
`OTW Measured Axial Thrust, liD" Nozzle.
`Uninstaned SFC Vs. Thrust.
`Inlet Reingestion-Shield Installation.
`Reverse Thrust Vs. Airflow.
`UTW Fan.
`UTW Fan Bypass Performance at 95% Speed.
`•
`UTW Fan Huh Performance at 95% Speed.
`UTW Fan Reverse-Thrust Performance.
`OTW Fan.
`OTW Fan Bypass Performance.
`OTW Fan Hub Performance.
`Fan Rotor with Cam/Harmonic System.
`UTW Reduction Gear.
`UTW Inlet Mach Number Control.
`UTW Fan Speed Control.
`UTW Fan Exhaust Nozzle Tracking.
`OTW Fan Speed Scheduling.
`OTW Core Stator Control Performance.
`OTW Turbine Inlet Temperature Calculation Comparison.
`OTW Typical Engine Start.
`OTW Thrust Response.
`UTW QCSEE.
`
`xii
`
`Page
`206
`207
`208
`209
`210
`212
`214
`215
`216
`218
`
`220
`222
`224
`
`226
`227
`229
`231
`232
`233
`235
`236
`238
`
`GE-1011.014
`
`
`
`LIST OF ILLUSTRATIONS (Continued)
`
`UTW Acoustic Test Configurations.
`Acoustic Test Site.
`Peebles Acoustic Test Sound Field.
`UTW Inlet-Radiated Baseline Noise.
`UTW Exhaust-Radiated Baseline Noise.
`variation of PNL with Blade Angle.
`UTW Inlet Configuration.
`Effect of Inlet Throat Mach Number on PNL.
`UTW Exhaust Treatment Configuration.
`Exhaust-Quadrant PNL Variation with Thrust.
`Exhaust-Quadrant System Suppression Spectra, Wall
`Treatment Only.
`Exhaust-Quadrant System Suppression Spectra, with
`Splitter.
`
`Suppression.
`Core Suppression from Far-Field Measurements, Approach
`Thrust.
`Variation of Peak PNL with Percent Reverse Thrust.
`OTW QCSEE.
`OTW Acoustic Test Configurations.
`OTW Inlet-Radiated Baseline Noise.
`OTW Exhaust-Radiated Baseline Noise.
`OTW Inlet Configuration.
`OTW Inlet-Radiated Noise at Takeoff.
`
`Figure
`159.
`160.
`161.
`162.
`163.
`164.
`165.
`166.
`167.
`168.
`169.
`
`170.
`
`171.
`172.
`
`173.
`174.
`175.
`176.
`177.
`178.
`179.
`
`xiii
`
`Page
`239
`240
`241
`242
`243
`245
`246
`247
`249
`250
`
`251
`
`252
`253
`
`254
`
`255
`258
`259
`260
`261
`262
`263
`
`GE-1011.015
`
`
`
`LIST OF ILLUSTRATiONS
`
`Figure
`180.
`l8l.
`182.
`183.
`184.
`185.
`186.
`187.
`
`OTW Inlet-Radiated Noise at Approach.
`Measured Exhaust; PNL.
`OTW Exhaust-Radiated Noise at Takeoff.
`OTW Exhaust Suppression at Takeoff.
`OTW QCSEE with Thrust Reverser Deployed.
`OTW Reverse-Thrust System Noise.
`QCSEE Approach and Takeoff EPNdB Contours.
`UTW Engine Assembly.
`
`Page
`264
`266
`267
`268
`269
`270
`273
`276
`
`xiv
`
`GE-1011.016
`
`
`
`LIST OF TABLES
`
`Table
`I. QCSEE Program Goals.
`II. QCSEE Test Results.
`III.
`UTW Design Parameters.
`OTW Design Parameters.
`IV.
`V.
`UTW Fan Aerodynamic Design Features.
`OTW Fan Aerodynamic Design Features.
`VI.
`VII. Aerodesign Requirements.
`VIII. UTW Composite Fan Blade Bird-Impact Design Requirements.
`IX. Design Requirements for Variable-pitch-Actuation System.
`X. Main Reduction Gear Design Summary.
`XI. Rig-Test Results.
`XII. Frame Loading Conditions.
`XIII. Geometry of Composite Frame Components.
`XIV.
`Frame Component Stress.
`xv. Effect of Different Thermal Coefficients.
`XVI.
`Subcomponent Test Results.
`XVII.
`Inlet Stresses and Deflections at Maximum Load Conditions.
`XVIII. Typical Outer-Cowl Stresses.
`XIX. Typical Core-Cowl Stresses.
`XX.
`Design Challenges.
`XXI. Emissions Program Cycle Selection.
`XXII. QCSEE
`Combustor.
`XXIII. Emission Results for QCSEE Double-Annular Combustor.
`
`Page
`
`1
`2
`16
`16
`23
`39
`44
`52
`52
`79
`84
`89
`92
`93
`93
`95
`
`III
`
`III
`120
`145
`146
`146
`158
`
`xv
`
`GE-1011.017
`
`
`
`LIST OF TABLES (Concluded)
`
`Table
`XXIV.
`XXV.
`XXVI.
`
`XXVII.
`
`UTW Test History.
`OTW Test History.
`UTW Measured Performance, Sea Level Static, 305.5 K
`(90 0 F) Day.
`OTW Measured Performance, Sea Level Static, 305.5 K
`(90 0 F) Day.
`XXVIII. Steady-State System Stability.
`Sensor Accuracy.
`XXIX.
`UTW Composite Nacelle System Noise.
`XXX.
`OTW Boilerplate Nacelle System Noise.
`XXXI.
`XXXII. Comparison of Footprint Areas: QCSEE to Typical
`Current Aircraft.
`UTW Engine Weight.
`XXXIII.
`UTW Nacelle Weight.
`XXXIV.
`OTW Engine Weight.
`XXXV.
`OTW Nacelle Weight.
`XXXVI.
`XXVII. Thrust-to-Weight Assessment.
`XXXVIII. Control System Summary and Conclusions.
`
`Page
`195
`
`195
`
`204
`
`211
`230
`230
`257
`271
`
`274
`278
`279
`280
`281
`282
`
`287
`
`xvi
`
`GE-1011.018
`
`
`
`1.0 SUMMARY
`
`The Quiet Clean Short-haul Experimental Engine (QCSEE) program was con-
`ducted by General Electric Advanced Engineering and Technology Program Depart-
`ment under contract from NASA Lewis Research Center. The program included the
`design, fabrication, and testing of turbofan propulsion systems for two short-
`haul transport aircraft and delivery of these systems to NASA for further
`testing. One propulsion system was designed for an Under-the-Wing (UTW), ex-
`ternally blown flap application; the other
`configured for Over-the-Wing
`(OTW) upper-surface blowing.
`Major objectives of the program were to develop the technology needed to
`meet the stringent noise, exhaust emissions, performance, weight, and tran-
`sient thrust-response requirements of future short-haul aircraft. Specific
`program goals are as listed in Table I.
`
`OTW
`
`95
`95
`100
`100
`1979 EPA Standards for Carbon
`Monoxide, Unburned Hydrocar-
`bons, and Oxides of Nitrogen
`
`93.4 (21,000)
`90.3 (20,300)
`0.0102 (0.36)
`35
`
`72.6 (7.4)
`46.1 (4.7)
`
`1
`1.5
`
`I
`
`j
`
`GE-1011.019
`
`Table I. QCSEE Program Goals.
`UTW
`Parameter
`Noise at 152.4 m (500 ft) Sideline
`Takeoff and Approach, EPNdB
`Maximum Reverse Thrust, PNdB
`Exhaust Emissions
`,
`Performance
`Uninstalled Thrust, kN (lbf)
`In,stalled Thrust, kN (lbf)
`Uninstalled sfC;, g/sec/N (lbm/hr/lbf)
`Max Reverse Thrust, % of Max Forward
`Thrust to Weight Ratio, N/kg (lbf/lbm)
`Uninstalled
`Installed
`Thrust Transient, seconds
`Approach to Takeoff
`Approach to Max Reverse
`
`81.4 (18,300)
`77.4 (17,400)
`0.0096 (0.34)
`35
`
`60.8 (6.2)
`42.2 (4.3)
`
`1
`1.5
`
`
`
`low tip-speed
`Major design features selected for the engines include:
`fans, composite fan frames, high throat Mach number inlets, main reduction
`gears, and digital electronic control systems.
`In addition the UTW propulsion
`system contains a variable-pitch fan with composite blades, a variable-area
`fan-exhaust nozzle, and a complete composite nacelle with integral acoustic
`treatment. The OTW propulsion system includes a fixed-pitch fan with titanium
`blades, a "D" shaped exhaust nozzle, a target-type thrust reverser, and a
`boilerplate nacelle with interchangeable acoustic treatment. Figure 1 shows
`the test configuration of the UTW propulsion system with the composite
`nacelle, and Figure 2 shows the OTW propulsion system with the boilerplate
`nacelle.
`The UTW propulsion system completed a total of 153 hours of testing at
`General Electric's Peebles, Ohio outdoor acoustic test side 4D and was de-
`livered to NASA in August 1978. The OTW propulsion system completed 58 hours
`of testing at the same site and was delivered in July 1977. Major results of
`the test program are as listed in Table II.
`
`Table II. QCSEE Test Results.
`UTW
`
`OTW
`
`Parameter
`Demonstrated Sideline Noise
`Levels
`Approach, EPNdB
`Takeoff, EPNdB
`Max Reverse, PNdB
`Exhaust Emissions
`
`Performance
`Uninstalled Thrust
`Installed Thrust
`Uninstalled sfc
`Max Reverse Thrust
`Thrust Transients
`Approach to Takeoff
`Approach to Max Reverse
`
`-
`
`*at 27% Reverse Thrust
`
`2
`
`94.5
`95.7
`97.2
`97.2
`105*
`107
`Met 1979 EpA Standards in Combustor
`Rig Test
`,
`
`\
`
`Met Goal
`Met Goal
`Met Goal
`27%
`
`Met Goal
`Met Goal
`3% Better Than Goal
`Exceeded Goal
`
`Not Demonstrated Met Goal
`Not Demonstrated
`Not Demonstrated
`
`GE-1011.020
`
`
`
`‘H3900 mm -1 e.m3;_.I
`
`GE-1011.021
`
`
`
`Figure 2. OTW QCSEE.
`
`GE-1011.022
`
`
`
`From an overall standpoint, both engines either met or closely approached
`all significant program objectives. The following advanced-technology compo-
`nents performed very successfully:
`•
`Low Pressure-Ratio Fans
`• Main Reduction Gearing
`• Variable-pitch Actuation Systems
`•
`Composite Frame
`•
`Composite Nacelle
`• Digital Control
`•
`Low-Emissions Combustor
`As a general conclusion, the QCSEE program demonstrated that propulsion
`systems can be produced to meet the demanding short-haul requirements, includ-
`ing those for noise and pollution, without seriously compromising the economics
`of the transport system.
`
`5
`
`GE-1011.023
`
`
`
`2.0
`
`INTRODUCTION
`
`The General Electric Company has recently completed the QCSEE prograin
`under Contract NAS3-l8021. This program included the design, fabrication,
`and testing of two advanced turbofan propulsion
`intended. to ,develop
`the technology that will be needed by powered-lift, short-haui-transport air-
`craft in the future.
`
`2 . I BACKGROUND
`The major problems facing the air transport industry in the early 1970's
`were noise and airport congestion. Noise had forced the closing of certain
`runways, the imposition of curfews at some airports, and the use of special
`flight restrictions such as reduced-throttle climb and low-altitude turns that
`were generally considered to be undesirable procedures. The congestion prob-
`lem was manifested by traffic and parking problems, baggage-handling delays,
`and (especially in bad weather) long delays in C;iepartures and arrivals due to
`congested air space.
`air passenger traffic was increasing at a
`7% annu,al rate, threatening to make these problems worse.
`A solution to these problems was envisioned in the introduction of a sep-
`arate, short-haul-transport system to cover the routes of 800 km (500 miles)
`or less. This system would utilize a fleet of new aircraft that would operate
`from smaller airports close to city centers and from auxiliary runways at the
`larger airports. A 6l0-m (2000-ft) runway capability was set as an objective,
`requiring that the aircraft incorporate some form of powered lift. Of the
`various suggested powered-lift concepts, two emerged as potentially attractive.
`These were the externally blown flap system used by Douglas in the YC-15 and
`the upper-surface-blowing concept used by Boeing in the YC-14.
`Pre-QCSEE contracted studies were conducted to explore engine cycles and
`concepts. These studies resulted in the recommendation for very low fan pres-
`sure ratios and correspondingly high bypass ratios. They also indicated that
`a variable-pitch fan might be a practical means of providing reverse thrust,
`with less weight penalty than a conventional reverser, for a high-bypass en-
`gine. On the basis of these study results and other NASA test programs, the
`broad objectives and specific goals for the QCSEE program were established.
`2.2 DESIGN APPROACH
`Jet/flap interaction noise is a major contributor to the total noise sig-
`nature of powered-lift aircraft. The under-the-wing installation results in
`direct impingement of the exhaust jet on the wing flap; the over-the-wing in-
`stallation provides some noise shielding for the sideline observer. As shown
`in Figure 3, jet velocities were selected for each of the engines to keep this
`noise source about 3 dB below the total system noise for a balanced acoustic
`
`6
`
`GE-1011.024
`
`
`
`Effective
`Perceived
`Noise
`Level,
`EPNdB
`
`110-
`100 I
`t------..r----
`90
`
`- ,
`
`vee:_
`
`-IOTW
`
`80
`
`1.1
`
`1.2
`1 .. 3
`Fan Pressure Ratio
`
`1.4
`
`Figure 3. Effect of Jet Flap Noise on Fan Pressure Ratio Selection.
`
`-..J
`
`GE-1011.025
`
`
`
`i
`
`design. A very low jet velocity (and very low fan pressure ratio) was re-
`quired for the UTW engine. The low uqise goal also dictated a low-tip-speed
`fan having reduced blade-passing frequency as well, as careful selection of the
`numbers of fan blades and vanes and adequate spacing between them.
`,
`Forward-radiated noise was reduced by the use of a high throat Mach num-
`shown in the drawing of the UTW propulsion system, Figure 4. Fur-
`ber inlet -
`ther suppression was added as needed by structural acoustic panels and by an
`acoustic splitter in the fan discharge duct.
`.
`Both QCSEE's incorporated the YFIOl core to take advantage of its ad-
`vanced state of development. The combustor used in this core was already
`smoke-free, but it did not meet the pollution objectives. A new double-
`annular combustor was conceived to fit into the same envelope and to reduce
`emissions. This design was a spin-off from the NASA Lewis Experimental Clean
`Combustor Program.
`The need for a high thrust-to-weight ratio was addressed by the extensive
`use of graphite and Kevlar composites in the fan blades, frame, and nacelle.
`This permitted the nacelle wall to be made integral with the engine, combining
`two structures into one. For example, the outer casing of the fan frame func-
`tions as the engine outer flowpath as well as a portion of the external nacelle.
`Short-haul aircraft tend to require fairly high thrust-lapse rates so
`that the engines can operate near the bottom of the sfc bucket at moderate
`cruise altitude. Low-pressure-ratio fans inherently have this character-
`istic. The best efficiency for low-pressure-ratio fans occurs at relatively
`low fan-tip speeds. A variable-area fan-exhaust nozzle was necessary to
`the fan pressure ratio from dropping too low at cruise, with detrimental
`effects on sfc, and to provide sufficient altitude thrust. Though high lapse
`rate is needed for STOL aircraft, the very low pressure ratio fans used for
`low noise have an even higher lapse rate than desired.
`Another .characteristic needed to achieve low sfc levels is a high cycle
`pressure ratio. Selection of the YFIOl core was made for reasons of program
`cost and risk and the appropriately advanced technology level. The use of a
`low-pressure-ratio fan with this core resulted in an overall cycle pressure
`ratio lower than desired. A more optimum cycle could have been produced by
`adding booster stages to the fan or by increasing; the pressure ratio of the
`core, but this technology is already well in hand and was not considered to
`be worth the added program cost.
`The short-takeoff requirement implies a short landing and an effective
`thrust reverser. The low-pressure-ratio UTW cycle lends itself to a reverse-
`pitch fan that can provide reverse thrust without heavy, variable-geometry,
`nacelle components.
`A digital control was required to permit optimum coordinated control of
`the variable-pitch fan, the variable nozzle, and the core engine with accept-
`able pilot work load. Numerous other functions were also provided such as
`
`8
`
`GE-1011.026
`
`
`
`'u1a:),sAg uo'_cs{ndo.1d M_1,n
`
`'17 e.1n3I.E
`
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`1
`I
`
`GE-1011.027
`
`
`
`maintenance of safety limits and condition-monitoring functions. Top-mounted
`accessories were used on the UTW engine to permit lower weight, better main-
`tainability, and low drag.
`It required a tiD" shaped exhaust
`The ON engine is shown in Figure S.
`nozzle to turn the flow downward and spread it over the wing and flap. Area
`control was provided by variable side doors. Since this engine has a fixed-
`pitch fan, thrust reversal is provided by pivoting the roof of the nozzle to
`form a target-type reverser blocker.
`System studies conducted by McDonnell-Douglas and Boeing helped direct
`the engine-design activity. Baseline UN and ON aircraft designs were es-
`tablished to identify propulsion and installation requirements. Economic
`studies were conducted to assess the payoff of the new engine technologies.
`American Airlines contributed requirements for the aircraft and an operational
`scenario for the short-route structure. They were also consulted on main-
`tenance features,
`design, and reliability.
`Figure 6 shows the baseline aircraft projected by Douglas using the UTW
`engine.
`It would employ four QCSEE's mounted under the wing and is based on
`·the Douglas YC-lS technology. The major characteristics are listed on the
`figure.
`Figure 7 shows the baseline aircraft projected by Boeing using the ON
`engine.
`It is somewhat larger, taking advantage of the greater thrust of
`four OTW engines, and is based on technology developed for the YC-14. The
`two aircraft were shown to be very competitive for short-haul operation.
`These studies reached the conclusion that the 6l0-m (2000-ft) runway re-
`quirement was too stringent; 915 m (3000 feet) is more realistic based on pro-
`jected airport availability. Another significant result was recognition that,
`in both installations, the engines would be mounted so high that a work stand
`would be required for all maintenance operations regardless of accessory lo-
`cation. This fact permitted the engine and aircraft accessories to be mounted
`in the pylon area to reduce nacelle drag for both installations and allow
`shorter, more direct, service lines from the wing.
`The above approach resulted in the specific engine designs described In
`the next section of this report.
`
`10
`
`GE-1011.028
`
`
`
`‘waqsfig uoystndoad M.LO
`
`'9 9-1“3TJ
`
`GE-1011.029
`
`
`
`70,620 kg (155,700 Ib) TOGW
`926 km (500 n.mi.) Range
`162 Passengers
`914.4 m (3000 It) Runway
`4 Engines @ 81,400N (18,300 Ib) Thrust
`
`40.Sm
`(133 ft)
`
`3'S.9m
`(118 ft)
`
`00
`
`nn
`
`nn
`
`___ __ _ _ _ .
`
`Figure 6. Baseline UTW Aircraft.
`
`12.Sm
`
`(41 ft) !
`
`GE-1011.030
`
`
`
`Ib) TOGW
`90,040 kg
`926 km (500 n.mi.) Range
`197 Passengers
`914.4 m (3000 ft) Runway
`4 Engines @ 93,408 N (21,000 Ib) Thrust
`
`46.86m
`(153.75 tt)
`
`37.75m
`(123.86 It)
`
`II
`
`i
`
`I
`
`'-'
`
`(pWi.J I I
`
`'-' ---
`
`13.72m
`(45,00 U)
`I
`
`J
`
`I-'
`W
`
`Figure 7. Baseline OTW Aircraft.
`
`GE-1011.031
`
`
`
`3.0 ENGINE DESIGN
`
`This section will describe overall design of the UTW and OTW engines with
`components. Results of compo-
`particular emphasis on the
`nent testing are also included where they contributed to the final engine
`design.
`
`3.1 OVERALL ENGINE DESCRIPTION
`Details of the UTW engine can be seen in Figure 8. The inlet, fan
`blades, fan frame, fan outer duct, and fan variable nozzle are all made of
`graphite or Kevlar with an epoxy matrix. The fan inner duct is made of
`graphite with NASA-developed PMR polyimide resin for higher temperature
`operation. Acoustic treatment is used in the inlet, fan frame, core inlet
`duct, fan exhaust duct and splitter, and core exhaust nozzle. The latter
`includes a two-level acoustic absorber for high and low frequencies. Atwo-
`stage F10l power turbine drives a star-type, epicyclic, main reduction gear.
`The reduction gear was designed and developed by Curtiss-Wright Corporation.
`It opens part way for takeoff
`The fan nozzle is shown in the cruise position.
`and approach and further for reverse, where it functions as an inlet.
`nature of the blade pitch-control system, many
`Recognizing the
`concepts were studied, and two variable-pitch systems were built and tested.
`Standard, and a ball
`A cam/harmonic-drive design was supplied by
`spline system by General Electric. Both systems/were whirl tested prior to
`use in a QCSEE to verify the ability to position the blades under centrifugal
`loading.
`The major design parameters of the UTW engine are listed in Table III.
`The low fan-tip speed, used in conjunction with a 2.5-reduction gear ratio,
`permitted the use of a conventional high-speed, low-pressure turbine. The
`low fan pressure ratio resulted in a very low jet velocity and helped meet
`the acoustic requirement discussed earlier. Note the high bypass ratio made
`possible by the energetic core and the low-pressure-ratio fan.
`A cross section of the OTW engine is shown in Figure 9. All nacelle
`comp(;>nents