The Airplane That Could!

Transcription

1 The Airplane That Could! Critical Design Review December 6 th, 2008 Haoyun Fu Suzanne Lessack Andrew McArthur Nicholas Rooney Jin Yan Yang Yang

2 Agenda Criteria Preliminary Designs Down Selection Features Trade Studies Wing and Empennage Design Fuel Tank System Center of Gravity / Static Stability Take-off and Landing Analysis V-n Diagrams Wing Air Loads Load Path Cost Analysis 2

3 Criteria Relief Delivery Mission Transoceanic Mission 30 ton payload 10 ton payload 2,500 takeoff distance 2,500 takeoff distance Cruise speed Mach 0.8 Cruise speed Mach nm cruise range 3,200 nm cruise range Wet grass, 3,000 by 200 landing zone Wet grass, 2,500 by 200 landing zone Air Force FDCV Mission 65 ton payload 5,500 takeoff distance Cruise speed Mach nm cruise range (one refueling) Wet grass, 3,500 by 200 landing zone 3

4 500 nm cruise Divert Takeoff Climb Loiter Attempt to Land or Land Climb Loiter Land Relief Mission Divert Profile 500 nm cruise RTB cruise Takeoff Climb Loiter Land and Unload Cargo Climb Loiter Land 3200 nm Cruise Divert Relief Mission Return to Base Profile Takeoff Climb Loiter Attempt to Land or Land Climb Loiter Land Transoceanic Mission Profile Takeoff Climb 5000 nm Cruise/Air Refueling Loiter Attempt to Land or Land Divert Climb Loiter Land FDCV Delivery Mission Profile 4

5 Preliminary Designs Red Configuration FEMA Mission Low Wing Three Engines Conventional Empennage White Configuration FEMA Mission High Wing Two Engines T-Tail Empennage Blue Configuration Air Force FDCV Mission High Wing Four Engines H-Tail Empennage 5

6 Preliminary Design Comparison Criteria Red White Blue Mission FEMA FEMA Air Force + FEMA Range (nm) 3,200 3,200 2,800 W TO (lbs) 184, , ,000 W E (lbs) 89,600 89, ,000 T/W W/S (psf) Mach Cruise Speed SL (ft) 2,330 2,330 2,990 STO (ft) 2,370 2,370 3,460 C Lmax TO C Lmax Landing Wing Span (ft) AR Fuselage Length (ft) Landing Stall Speed (knots) Cost (Millions 2008 USD) $217.3 $215.8 $

7 Down Selection White Configuration -> Thomas 7

8 Down Selection High Wing Ground clearance for large flaps Reduced floating effect Reduced engine-debris encounters Cargo floor close to ground Propulsion System Two tractor engines Externally blown flaps meet required C Lmax Engines more reliable with today's technology Engines are easy to inspect 8

9 Down Selection T-tail Configuration Reduced horizontal and vertical stabilizer volume coefficients End plate effect Clean air Single fuselage attachment point Avoids rudder blanketing at high angles of attack Cost FEMA: $215.8 million Air Force: $287.1 million Cannot justify a more expensive plane for FEMA 9

10 Thomas Overview and Comparison Criteria Thomas White Ilyushin IRTA-21 Lockheed C-130 Boeing C-17 W TO (lbs) 192, , , , ,000 W E (lbs) 95,200 89,600 N/A 79, ,500 Max Payload (lbs) 60,000 60,000 40,785 48, ,900 T/W N/A 0.1 (P/W) 0.28 W/S (psf) N/A Range (nm) 3,200 3,200 1,349 2,832 4,200 Cruise Mach S L (ft) 2,490 2,330 4,430 2,550 3,000 S TO (ft) 2,450 2,370 4,270 3,050 7,740 C Lmax TO 2 2 N/A N/A N/A C Lmax Landing N/A N/A 4.75 Aspect Ratio N/A Clean Stall Speed (knots) Landing Stall Speed (knots) N/A N/A N/A N/A

11 Thomas Dimensions 11

12 Thomas Features Cockpit Two Flight Crew One Loadmaster One Potential Observer Loadmaster Station Desk Fold-down Chair Lavatory Closet 12

13 Interior Design and Layout - Cockpit 13

14 Interior Design and Layout: Lavatory, Closet, and Loadmaster Station CAD Representation of the Lavatory (upper left), the closet (upper right), and loadmaster station (right) 14

15 Landing Gear Layout Thomas Nose Landing Gear Thomas Main Landing Gear 15

16 Trade Studies Drivers Take-off Distance Landing Distance Gross Take-off Weight Empty Weight Parameters Thrust-to-Weight: 0.31, 0.41, 0.51 Wing Loading: 67, 77, 87 Aspect Ratio: 6.0, 6.7,

17 Trade Studies Optimized Parameters: Aspect Ratio 7.4 Thrust-to-Weight 0.36 Wing Loading 86 Gross Take-off Weight (lbs) 189,500 17

18 Wing Design Super Critical airfoils: Boeing root RAE tip Aerodynamic twist -3 degrees Criteria Thomas Take-off Weight (lb) 192,000 Wing Loading (lb/ft 2 ) 86 Reference Area (ft 2 ) 2,380 Aspect Ratio 7.4 Span (ft) 133 Sweep (degrees) 28 Dihedral (degrees) -3 18

19 High Lift and Control Devices High Lift Devices: Externally blown flaps 25% of chord Slats 20% of chord Control Devices: Ailerons 30% of chord Spoilers Criteria Thomas C Lmax 3.32 Clean C Lmax 1.7 Delta Flaps C Lmax 1.32 Flaps % of Span 14%-74% Flaps c'/c 1.25 Delta Slat C Lmax 0.3 Slats % of Span 14%-90% Slats c'/c 1.2 Aileron % of Span 75%-99% 19

20 Aerodynamic Parameters Parameter Cruise Condition Lift Coefficient Drag Coefficient Moment Coefficient Oswald Efficiency 0.97 Incidence Angle (deg) 0.83 Spiral Stability

21 Empennage Design T-tail NACA 0009 Airfoil Passed One-Engine-Inoperative test Parameter Horizontal Tail Vertical Tail Volume Coefficient Aspect Ratio Taper Ratio Sweep Angle ( ) Incidence Angle ( ) 0 0 Dihedral ( ) -3 0 Tail Area (ft 2 )

22 Propulsion System Pratt & Whitney PW2043 turbofan PW2000 series/f117-pw-100 used on Boeing 757, Ilyushin Il-96M, and Boeing C-17 PW2000 Series Fan Tip Diameter (in) 78.5 Length (in) Take-off Thrust (lbf, PW2043) 42,600 Bypass Ratio 6 Weight (lbf) 8,721 Specific Fuel Consumption (lb/lbf-hr)

23 Fuel Tank System Transoceanic Mission requires 70,000 lbs of fuel Nose and forward fuselage tanks move fuel CG location from 45 ft to 30 ft Fuel management provides CG stability during loading Parameter Thomas Wing Fuel Tank Weight (lbs) 87,800 Wing Fuel Tank Volume (gal/ft 3 ) 13,000/1,740 Nose Fuel Tank Weight (lbs) 8,400 Nose Fuel Tank Volume (gal/ft 3 ) 1,200/170 Forward Fuselage Fuel Tank Weight (lbs) 10,200 Forward Fuselage Fuel Tank Volume (gal/ft 3 ) 1,500/200 23

24 Fuel Tank System: Nose and Forward Fuselage Fuel Tanks Nose Fuel Tank Fuselage Fuel Tank 24

25 Fuel Tank System: Wing Fuel Tanks 25

26 Weight (lb) Center of Gravity Excursion and Static Stability Center of Gravity Total Excursion: 8.2% Case X Center of Gravity (ft) Xbar Center of Gravity Static Margin (%) Empty Empty + Loading Cargo + Fuel (Loading Payload) Neutral Point: 51.6 ft Passes longitudinal, lateral, and ground clearance tests Empty + Loaded Cargo + Crew (Landing) Empty + Loaded Cargo + Crew + Full Fuel (Takeoff) Take-off Landing Loading Empty Xbar CG (normalized by MAC) 26

27 Take-off Meets take-off distance requirement < 1% margin Height after Transition: 154 ft Balanced field Length: 900 ft Segment Thomas S G (ft) 284 S R (ft) 650 S T (ft) 1,560 S C (ft) 0 Total Take-off distance (ft) 2,494 27

28 Landing Meets landing distance requirement on wet grass < 1% margin Calculated without thrust reversers Built in safety factor of 1.66 Segment Thomas S a (ft) 450 S F (ft) 630 S FR (ft) 540 S B (ft) 1,120 Total landing distance (ft) 2,490 28

29 V-n Diagrams: Minimum Weight Condition (121,000 lbs) 29

30 V-n Diagrams: Maximum Weight Condition (192,000 lbs) 30

31 Wing Air Load Distributions Minimize aircraft weight while meeting safety standards The aircraft structure must: Withstand the proof load without detrimental distortion Not fail until ultimate load has been achieved. Obtain distributed load on wings by combining AVL results with the proper equations. Finite element method used to calculate aerodynamic loads in the body-fixed coordinate system. 31

32 Bending Moment in the X-direction for Maximum Weight 32

33 Load Path Layout Longerons and Stringers Fuselage Bulkhead Wind Box Carry-through Wing Spars

34 Manufacturer Cost Overview Cost Analysis Results are given in Millions of 2008 USD Customer price and Net Present Value Program Profit are based on 10% margin rate Thomas RDT&E $3,208 Flyaway $4,319 Program Cost (RDT&E + Flyaway) $7,527 Program Cost per Plane $215.1 Customer Price per Plane $236.6 Contribution Margin $103.8 Breakeven Quantity 31.8 NPV Program Profit $

35 FEMA Life-Cycle Cost Cost Analysis Results are given in millions of 2008 USD Operating Cost per Flight Hour in 2008 USD: $16,500 Life-Cycle Cost is based on an aircraft service life of 21 years Program Cost (RDT&E + Flyaway) Customer Price per Plane Thomas $7,527 $236.6 Operating Cost $12,520 Operating Cost per Plane $357.7 Disposal Cost $210.1 Total Life Cycle Cost $21,011 35

36 36

37 Design Methodology Historical Aircraft Preliminary Sizing Initial Cost Analysis Three Configurations Red, White, and Blue CATIA models Detailed Design Aspects Down-Select Process Refined Thomas Aircraft V-n Diagrams AVL Analysis Structural Loads Revised Cost 3D Printing Model 37

38 Aircraft Sizing Preliminary Sizing Take-off Climb Cruise Speed Ceiling Landing Thrust-to-Weight and Wing Loading Relief Transoceanic Thrust-to-Weight Ratio Wing Loading (psf) C Lmax Take-off C Lmax Landing

39 Individual Weights Items Utilize Composites Relief Mission Weights (lb) Transoceanic Mission Weights (lb) Wing 21,450 21,450 Horizontal Tail 3,855 3,900 Vertical Tail 1,646 1,600 Fuselage 38,195 38,200 Main Landing Gear 7,495 7,500 Nose Landing Gear 1,320 1,300 Installed Engines 18,420 18,400 Payload 60,000 20,000 Crew Fuel 36,600 70,000 W E 95,200 95,200 W TO 192, ,800 39

40 Landing Gear Sizing Criteria Thomas Nose Total Tire Load (lb) 23,000 Main Total Tire Load (lb) 207,000 Nose Gear Bogeys 1 Main Gear Bogeys 4 Nose Gear Wheels / Bogey 2 Main Gear Wheels / Bogey 2 Nose Weight per Wheel (lb) 11,500 Main Weight per Wheel (lb 25,900 Nose Tire Diameter (inch) 25 Main Tire Diameter (inch) 40 Nose Tire Width (inch) 7 Main Tire Width (inch) 14 KEbraking (106 ft-lb/s) 12 40

41 Positioning Landing Gear Position Thomas Xng(nose landing gear) ft 16.2 Yng(nose landing gear) ft 0 Zng(nose landing gear) ft 3 Xmg (main landing gear)ft 58 Ymg (main landing gear)ft 5.9 Zmg (main landing gear)ft 3 Ztip(the height of the tip of the fuselage from the ground) 12.4 This configuration passes the longitudinal tip-over test, lateral tip-over test, and meets the ground clearance criteria. 41

42 Thomas Design Cost Overview - Preliminary Design Review Estimates DAPCA IV Results (in Millions of 2008 USD) Red White/Thomas Blue RDT&E $2,946 $2,946 $8,626 Flyaway $3,967 $3,920 $24,004 Program Cost (RDT&E + Flyaway) $6,913 $6,866 $32,631 Program Cost per Plane $197.5 $196.2 $261.0 Customer Price per Plane $217.3 $215.8 $287.1 Contribution Margin $103.9 $103.8 $95.1 Breakeven Quantity

43 Assumptions Used to Separate RDT&E Costs and Flyaway Costs Hours Percentage Spent in Development (RDT&E) Percentage Spent in Production (Flyaway) Engineering 80% 20% Tooling 95% 5% Manufacturing 5% 95% Quality Control 5% 95% 43

44 Preliminary Design Review DAPCA IV Model Inputs by Configuration Model Input Red White Blue Empty Weight (lbs) 90,000 90, ,000 Takeoff Weight (lbs) 184, , ,000 Max Speed (knots) Production Quantity Flight Tested Aircraft Total Engines Engine Max Thrust (lbf) 25,000 37,000 50,000 Engine Max Mach Engine Turbine Temperature (ºR) 2, , , Cost Avionics Rate/pound $5,219 $5,219 $5,219 Avionics Weight 3.00% 3.00% 2.00% 44 Percentage

45 Empennage Design 45

46 One-Engine-Inoperative 25 rudder deflection Take-off conditions, where speed is the lowest and, consequently, the moment created by the rudder deflection is the lowest Critical Engine-Out Yawing Moment (lb ft) Drag-Induced Yawing Moment (lb ft) Sum of Critical Engine-Out and Drag-Induced Yawing Moments (lb ft) Moment due to Rudder Deflection (lb ft) 760, , ,000 2,806,000 46

47 Balanced Field Length Take-off field length required, including obstacle clearance, if an engine fails at a speed at which the stop distance and the remaining take-off distance are equal Minimum required is 2000 feet with a 50 feet obstacle clearance Value for Thomas is around 900 feet 47

48 Figure 1: Shear loading in the X-direction for critical points with maximum weight 48

49 Figure 2: Shear loading in the Z-direction for critical points with maximum weight 49

50 Figure 4: Bending Moment in the Z-direction for critical points with maximum weight 50

51 Figure5: Torsional Moment in the y-direction for critical points with maximum weight 51

52 Figure 6: Shear loading in the X-direction for critical points with minimum weight 52

53 Figure 7: Shear loading in the Z-direction for critical points with minimum weight 53

54 Figure 8: Bending Moment in the X-direction for critical points with minimum weight 54

55 Figure 9: Bending Moment in the Z-direction for critical points with minimum weight 55

56 Figure10: Torsional Moment in the y-direction for critical points with minimum weight 56