Joint Heavy LiftJHL JSF Lift Fan Derivative Ryan

Joint Heavy Lift(JHL) -JSF Lift Fan Derivative Ryan Aaron Chris Bradshaw Jesus Claudio Romen Cross Kevin Ferguson Juan Gutierrez Phil Lines

Scope of Presentation l l l l Mission Overview Design Characteristics Initial Engine Design Final Engine and Fan Design Driveshaft/Gearbox Design Internal Design Analysis/Methodology Areas of Emphasis

Mission Profile

Mission Profile

Long Range, Heavy Lift Aircraft l Key requirements: – 300 nm radius of action – Payload: 37, 500 lb – Capability to carry vehicles like LAV, MTVR, or HEMAT (internal or external) – Capable of 15 minute cargo on load or off load using only aircrew – Shipboard compatible – Desired speed in excess of 200 kts

Assumptions l Airframe – C-130 J-30 Fuselage l Powerplant – 60, 000 lbs. Max Thrust per Lift Fan • 40, 000 – 45, 000 (std hot day) shp – 15, 000 lbs. Max Thrust per engine (Hover) – Unknown Max thrust available at cruise • 15, 000 lbs thrust required for 0. 7 Mach cruise speed l Technology – 2 Lift Fans – High Shaft HP Engines – Current C-17 Cargo Hold Technology

Design Characteristics

Sketch

Aircraft Dimensions l. Length l. Span l. Height l. Wing Area l. Tail Area Horizontal Vertical 113 ft 95. 4 ft 32. 25 ft 1805 sq ft 520 sq ft 186 sq ft

Sketch l. Spot Factor 1. 23 x CH 53 E • 1. 5 x CH 53 E (Objective) • 2. 0 x CH 53 E (Threshold)

Initial Engine Design

Analysis Procedure/Methodology l l l Initial Engine Calculations/Sizing Engine Performance Mission Thrust Requirements Weight and Balance Calculation Mission Comparison

Engine Calculations/Sizing l Used Aircraft Engine Design written by Jack Mattingly for engine sizing requirements to calculate Thrust Req. , Wing Area, and Fuel Req. l With Thrust req. , used GASTURB to estimate engine performance parameters (TSFC) l Engine performance parameters were then plugged back into MATLAB program to finalize weight, wing area, fuel load, and thrust req.

Engine Performance 15, 000 lbs Thrust for Vertical T/O l 6, 000 lbs Thrust for Mach 0. 7 Cruise l 7, 500 lbs Thrust for Mach 0. 54 Ingress l 50, 000 shp Required (losses and accessories) l JHL Propulsion System 15, 000 lbs 60, 000 lbs 15, 000 lbs

Mission Thrust Requirements MISSION PARAMETER l l l l l Takeoff Hover* Acceleration & Climb** Cruise Outbound Ingress*** LZ Landing* LZ Takeoff* Climb & Acceleration** Cruise Inbound Loiter Final Landing* THRUST REQUIRED(lbs) 155, 059 59, 429 11, 891 43, 743 143, 256 96, 841 37, 336 11, 885 5, 004 87, 016 – * Denotes Lift-Fans Operating at 100% – ** Denotes Lift-Fans Operating at 40% – *** Denotes Lift-Fans Operating at 25%

Overall Weight l Takeoff Weight – 136, 027 lbs. l Fuel – 21, 750 lbs. l Payload (w/ crew) – 38, 300 lbs. l Empty Weight – 76, 777 lbs.

Weight & Balance Calc.

Cargo Bay Design Envelope l l l Standard C-130 J-30 fuselage utilized Height accomodates for wood shoring under combat vehicles Under special circumstances, height can reach – 105 inches Practical max width for wheeled vehicle at floor – 102 inches Practical max width for tracked vehicle at floor – 100 inches Design guidance published in MILHDBK-1791 The Crosshatched Area Represents Required The 6 -Inch Clearance Required In MIL-HDBK-1791 Between The Payload And Aircraft Structure. 105” JHLA Cargo Bay Design Envelope

C-17 w/ Similar Cargo Handling Technology Palletized System Retracted

Mission Comparison Mission l l l Fuel(#) Rng(NM) Wto(#) 1) VTOL(design mission) -w/cargo drop 22, 661 600 132, 766 2) VTOL -no cargo drop 22, 946 600 133, 050 3) Ferry(CTOL) -no cargo, w/ fans 22, 661 1, 050 4) Ferry(CTOL) -w/cargo, w/fans 22, 661 610 5) Ferry(CTOL) -fuel vice fans 62, 161 2124 132, 766 6) Ferry(CTOL) -fuel vice cargo 60, 161 2, 815 132, 766 95, 103 132, 766

Fan Design

Lift Fan Propulsion l Fixed Parameters – Air, Standard Sea Level, Standard Hot Day • Fixes g, Cp, R, Tt 1, and pt 1 – Inlet, Fan, Nozzle Efficiencies, pd, ef, pn l Variables – – l Hub to tip Ratio, r Diameter of Intake, D (Inlet Area, fan size) Through flow Mach number, MA 1 Fan Pressure Ratio, pf Results – Thrust, Power, Mass Flow Rate – Exit: Mach Number, Velocity, Area

Lift Fan Calculation Results for JHL 60, 000 lbs Thrust

Lift Fan Design Analysis Euler Turbine Theory l Select l – – – – l Fan Tip Speed Mass Flow Hub/Tip Ratio Solidity Blade Aspect Ratio Diffusion Factor Relative Inflow Angle Accounts for Losses – Boundary Layer Blockage – Inlet and Nozzle Losses – Shock Losses l Results – Diameter – Blade Geometry • #Blades • Blade Chord • Blade Spacing – – – Thrust Power Required Pressure Ratio Temperature Ratio Flow Properties Along Blades • Flow Angles • Diffusion Factors • Pressure and Temperature Ratios • Shocks

Lift Fan Design Diameter 11. 92 ft Mass Flow 3250 lbm/s Utip 1000 ft/s Hub/Tip Ratio 0. 3 b 1 m 54. 9 o MA 1 0. 423 Pressure Ratio 1. 2449 Temperature Ratio 1. 0699 Thrust 59, 529 lbf Power 39, 667 hp

Lift Fan Geometry Blade Geometry R/Rbar Chord/ Spacing Setting Diffusion Angle Factor Aspect Ratio: 6 0. 4615 3. 83”/3. 06” Rotor Solidity: 1. 25 1 8. 30”/6. 64” # Blades: 44 1. 5385 12. 77”/10. 22” -4. 6 o 44. 6 o 62. 4 o 0. 3894 0. 4636 0. 2523 Aspect Ratio: 8 0. 4615 Stator Solidity: 1. 25 1 # Blades: 58 1. 5385 28. 7 o 17. 9 o 12. 5 o 0. 7966 0. 4218 0. 2635 2. 91”/2. 33” 6. 30”/5. 04” 9. 69”/7. 75”

Lift Fan Size 1. 2. 3. 4. 5. 6. 7. OD ~12 ft Inlet/Diffuser (unknown) Inlet Guide Vanes (8”) Fan Blades (6”) Stator Vanes (10”) Nozzle (unknown) Weight ~ 2500 lbs

The Fan Nozzle l Controllability l – Must be able to control the flow to provide fore/aft thrust control. – Necessary for transition for takeoff and landing. l – Can provide structural strength for wing. – Will allow nozzle contraction to take place over a small distance. – Allows louvers to direct flow without reducing nozzle area. Shroud – Wing Space is insufficient. l Louvered Nozzle – Practical, but effectively reduces nozzle area as the louvers pivot fore and aft. “Structural Nozzle” l Adjustable Nozzle – Increase nozzle area as louver pivot fore or aft to compensate for effective area reduction.

Lift Fan Control l Variable Geometry Inlet Guide Vanes – Provides rapid thrust changes without changing fan RPM. l Variable Fan RPM – Performance will vary with RPM as engine changes operating RPM.

Final Engine Design

Engine Design Problem l Engine must be designed to meet shaft power requirements. l LP Turbine is unmatched with the LP compressor. – Able to deliver shaft power for lift fan – LP spool Over-speeds during cruise operations unless controlled. – HP spool forced to operate at lower RPM during cruise l Alternately, designing for cruise leaves HP Spool incapable of producing sufficient flow to produce shaft work necessary for lift fans.

Mismatched Engine Solutions l Variable Stator in LP spool turbines – Adjust turbine power output to meet shaft work requirement without overspeeding turbine in cruise. – Would allow the HP spool to operate at higher RPM, and efficiency, in cruise producing lower TSFC. – Currently lack the design tools to be able to predict performance, especially offdesign. l Secondary Nozzle – Limit LP spool RPM to 102% – Contract the nozzle to adjust to lower mass flow. – Bleed fan air into secondary nozzle (eliminates choking in mixer) to improve performance without losing thrust – Variable bypass engine could achieve similar results, limited design tools make designing with this method simpler.

Mismatched Engine Solutions l Hover Settings – 60/40 Split of Power from LP Turbine • 60% to Lift Fan, Accessories and Losses • 40% to LP Compressor – Nozzle Full Open – No Bypass Air Bleed l Cruise Settings – 5/95 Split of Power from LP Turbine • Main Gear Box and Accessory Loads – Reduce Nozzle Area 40% – Bleed 60% of Bypass Air to Secondary Nozzle

The Engines l Design Point l – – – High, Hot Hover • 4000’ PA • 95 o. F l Design Requirements – 15, 000 lbf Thrust – 50, 000 shp for Lift Fan l l Outside Diameter ~ 6. 5’ Length ~ 14’ Nozzle Diameter ~ 4’ Weight ~ 8, 500 -9, 500 lbs Specifications at Design Point – By. Pass Ratio ~ 0. 3 – Fan Pressure Ratio ~ 1. 6 – Overall Pressure Ratio ~ 41. 6 (3. 5 LP, 12 HP) – Max Burner Temp ~ 3200 o. R – LP Spool RPM ~ 10, 000 – HP Spool RPM ~ 40, 000 Performance at Design Point – 15, 317 lbf Thrust – 49, 840 shp for Lift Fan – TSFC 1. 492 for engine thrust, overall TSFC 0. 304 for hover – Mass flow ~ 387 lbm/s (465 lbm/s corrected, Inlet) – Core Mass Flow ~ 298 lbm/s (128 lbm/s corrected, HPC) Size l LP Spool Mechanical Efficiency Modeled at 0. 4 to develop required power for lift fans

Engine Off-Design Performance

Driveshaft Design

Drive Shaft Requirements Transfer 50, 000 shp to the each Lift Fan l Operate at 10, 000 rpm l Be constructed for a high survivability rate l Maintain the operating speed clear of critical speeds l Photo courtesy of the Goodrich Corporation.

Supercritical Analysis Treat each shaft section as a Clamped-Clamped system. l Design around the requirements (ω = 10, 000 rpm and shp = 50, 000). l Used an iterative process to obtain optimal critical speeds, while maintaining allowable shear stress values for various materials (under Fsy, the Yield Stress in Shear). l

JHL Driveshaft Specifications

Gearboxes l Main Gearbox Ø Provides no reduction due to the power requirement to the Fans. 1: 1 Reduction Ratio Ø Independent 90 degree gear meshing with the shorter Lift Fan shafts. Ø Longer shafts from the 119 Engine enter at zero degrees pitch. l Auxiliary Gearboxes Ø 6: 1 Ratio Ø 90 degree turn upward toward the Lift Fans

Required Technology Materials l Propulsion System l Lifting Fans l Driveshaft Clutch Assembly l

Critical Design Points l Main Engines • Shaft Horsepower and Thrust Requirements l Lifting Fans • Size / Disk Loading / Fitting into wing l Aerodynamic Properties • Need for prepared landing zone / Fan-Wing incorporation l Stability • Fan louvers / Engine Ducts l Gearboxes/Clutch • Main Transmission / Fan gearboxes / Clutch assembly

Questions ?