Team 2 AAE451 System Definition Review Chad CarmackAaron MartinRyan MayerJake SchaeferAbhi MurtyShane MooneyBen GoldmanRussell HammerDonnie GoepperPhil MazurekJohn TegahChris Simpson

Outline  Mission Statement  Major Design Requirements  Concept Selection Overview Pugh’s method  Advanced Technologies Technologies incorporated Impact on sizing  Constraint Analysis Major performance constraints Basic Assumptions Constraint diagrams  Sizing Studies Design Mission Current sizing approach  Propulsion Selection 2

Mission Statement  To be the primary systems integrator of a high speed, long range executive transport system with unprecedented efficiency and minimal environmental impact. 3

Major Design Requirements  Meet NASA N+2 (2020) Goals 42 db Below Stage 4 Noise Requirements 75% Below CAEP-6 NOx Emissions 40% Fuel Reduction  17 Passengers  Cruise Mach 0.85  7100 nm Headwind Range  General Aviation Airport Capable  42,000 ft. Initial Cruise Altitude Design Target Goals 4

Design Mission 0-1: Take off to 50 ft.5-6: Climb to 5000 ft. (Best Rate) 1-2: Climb to ft. (Best Rate)6-7: Divert to Alternate 200 nm 2-3: Cruise at Mach : 45 minute Holding Pattern 3-4: Decent to Land (No Range Credit)8-9: Land 4-5: Missed Approach (Go Around) nm200 nm Los AngelesHong Kong Alternate 5

Pugh’s Method Process  Eight initial designs were presented and discussed  A concept was chosen for baseline comparisons  Each design was evaluated for each criterion Every design was assigned a +, -, or S All criteria are equally weighted  All +, -, and S ratings were individually totaled for each design In Pugh’s method, each aircraft’s ratings are not summed  Positives and negatives were investigated Positives were applied to other designs  Designs were narrowed to four, and a new baseline was chosen  All criteria were re-evaluated with the new baseline  After iterating, two designs were chosen for further investigation 6

Concepts Overview Concept 1Concept 2Concept 3 Concept 4 Concept 5Concept 6 Concept 7Concept 8 7

Design Number Criteria Baseline Cruise Drag++ss++++ Weight-ssss--- Ability to accommodate UDF -s-sssss Cabin Noisess-sssss Environmental Noise+sssss++ Landing Gearss-ssss+ Window Placement++-s+s+- Attractivenesss+-s-+++ Pressurizationsssssss- Static Margin--ss-+-- total S's total +'s total -'s Pugh’s Method Round 1 8

Design Number 2467 Cruise Drag+-s+ Weight-+s- Ability to accommodate PF-sss Cabin Noisessss Environmental Noise+ss+ Landing Gear+-s+ Window Placementsss+ Attractiveness--s+ Pressurizationssss Cost-+s- Static Margin-+s- total S's35113 total +'s3305 total -'s5303 Pugh’s Method Round 2 9

Concept 1 Rear fuselage mounted engines T-tail Low wing Circular Fuselage 10

Concept 2 Vertical stabilizer Lifting Canards Rear mounted engines 11

Advanced Technology  Unducted Propfan  Composite Materials 12

Unducted Propfan  Unducted Fan shows promise to reduce emissions and fuel consumption  “ERA is focused on the goals of NASA’s N+2, a notional aircraft with technology primed for development in the 2020 time frame as part of the agency’s subsonic fixed wing program” Aviation Week Dec 14, 2009 on the development of UDF

Benefits of UDF Relative to 1998 levels, NASA plans to reduce cumulative noise levels to 42 dB below stage 4, 75% lower NOx emissions, and reduce fuel burn by 40% ◦ Aviation Week on N+2 goals regarding UDF 14

How to Model UDF?  According to Aviation Week Current UDF Tests State that the UDF is Capable of:  25%-30% better fuel burn than current engines  20% lower NOx emissions than current engines  Good probability of meeting N+2 goals by

How to Model UDF?  Use a benchmark engine built on or before 1998  Calculate fuel burn and emissions via projected N+2 percentages  Assume Stage 4 noise compliance  Use GE36 blade diameter with a thrust scale factor for engine diameter 16

Composite Materials  Significant Empty Weight Savings  Proven Technology  Significant Savings in Production Cost  Up to 50% of Structure Could Be Constructed from Composite Materials Based on Historical Aircraft 17

How to Model Composite Materials  Initial Plan Was to Use Database of Weight Fraction of Composite Hawker 4000 With Comparable Designs *All Weights Courtesy of Jane’s All The World’s Aircraft 18

New Method to Model Composites  No Significant Weight Fraction Difference With Hawker 4000  Hawker used weight savings from composites to increase cabin volume for a very comfortable ride for aircraft category weight  New Method is to Use a 20% Empty Weight Reduction* *based of historical estimates from history.com/theory/composite.htm 19

Constraint Diagrams  Basic assumptions and initial estimates for aircraft concepts (C L )max T/O = 1.5 (C L )max Landing = 2.0 C D0 =.0180 e =.8 M cruise =.85 Cruise Altitude = 42,000 ft AR = 10.5 (canard) AR = 8 (conventional) No thrust reversers 20

Constraint Diagram of Conventional Aircraft 21 Landing ground roll 2600 ft

Constraint Diagram of Canard Pusher 22

Sizing Code  Current status: MATLAB script  Inputs: ~100 variables describing each aircraft  Fuel Weight  Engine Model (flight profile analysis)  Drag Prediction (component buildup)  Empty Weight (component buildup)  Correlation Factors (to similar aircraft)  Technology Factors (engines)  Calculates gross weight 23

MATLAB Code Flowchart Initial Guess W o Geometry Calculations W e Prediction Engine ModelDrag Calculation W fuel Prediction W 0 Calculation W 0 = W 0 calc Set W 0 guess to W 0 calc 24

Input Variables  From constraint diagram W 0 /S = 76 (conventional), 84 (canard) T SL /W 0 =.33  Wing, Canard, and Tail Geometric variables (AR, Taper ratio, sweep, etc)  Fuselage Dimensions, shape, etc.  Engines Weight, number, size, etc.  Mission Variables Range, Cruise Mach, etc.  Location of components (for x cg calculuation) 25

Assumptions  Flight conditions are constant over 500 ft altitude intervals during climb and descent.  Engine data is scalable  It was assumed that the equations in Daniel Raymer’s textbook were accurate 26

Validation  Correlated Conventional design to G550 and Canard design to Beechcraft Starship ConventionalCanard Fuel Weight0.77 Empty Weight Gross Weight

Estimated Weight Table ConventionalCanard Empty Weight (lbs) Fuel Weight (lbs) Weight of Crew (lbs) (200 per) 800 Weight of Passengers(lbs) (220 per) 3960 Gross weight (lbs)

Drag Prediction  Used to help predict: Engine size Amount of fuel Coast of aircraft 29

How to model Drag?  Component build up of different types of drag: Parasite drag Skin friction Pressure drag Interference drag Induced drag Miscellaneous rag Wave drag Assumed 20 counts of drag 30

Skin Friction  Assumed turbulent flow for conceptual design. Schlicting Formula 31

Pressure Drag  Body component shape dependant 32

Interference Drag  Drag from different components interacting with each other Q = 1 Q = 1.2 Q = 1 Q =

Parasite Drag Build-up ComponentConventionalCanard Fuselage Wing H-Tail V-Tail Nacelle Pylon * All values are at Cruise Conditions 34

Benchmark Engine  Rolls Royce BR700 Series  First Production Run in 1994  The BR700 Series has a thrust range of 14,750 lbf - 22,000 lbf range to allow for “rubber engine” design 35

Fuel Weight Prediction  Imported engine data curves  Curves were scaled based on the sea-level static thrust  Interpolated to find points not on curves  Calculated TSFC for different segments of the design mission  Fuel weight predicted for each segment 36

Engine Selection  Unducted Propfan Modeled Off of Previous Data and N+2 Goals, as Stated Before  Geared Turbofan Stated to Start Production Between Now and revue.rotor.com/FRHeft/FRHeft07/FRH0702/FR0702c1.JPG 37

Geared Turbofan  Uses a gear to decouple the fan from the low pressure turbine, thus allowing a large fan to spin slowly and a small turbine to spin quickly increasing efficiency 38

Pratt & Whitney PurePower PW1000  First ultra-high bypass ratio turbofan engine  Light-weight, low pressure fan design  20 dB Quieter than current engines  Proven Efficiency with No life-limited parts  Reduce NOx emissions (50% margin to CAEP/6)  13,000-17,000 lbf Thrust for 1215G or 21, ,000 lbf Thrust for 1524G  15% Reduction in Fuel Burn 39

UDF PurePower UDF PurePower  Pros  Very Efficient  N+2 goals likely met  Light Weight (direct drive)  Cons  Noise  Technology Still in Devlopment  Large Diameter  Pros  Reasonably Efficient  Quiet  In Production by 2016  Low Emissions  Cons  Large Diameter Casing (70in)  Not a lot of Data  Heavy (gearing) 40

Static Margin(SM)  Conventional CG = 51% of fuselage length SM = 37% of C mac  Canard CG = 74% of fuselage length SM = 29% of C mac 41

Requirements Compliance Matrix Performance Characteristics TargetThresholdCurrent Range (60 kt headwind) 7100 nm6960 nm7100 nm MTOW Balanced T/O Field Length (Takeoff Ground Roll) 6000 ft (4000 ft) 7000 ft (5000 ft) 6000* ft (3500 ft Concept 1) ( 3400 ft Concept 2) Max. Passengers17816 Volume per Passenger per Hour (Design) 13.3 ft 3 /(pax ⋅ hr)2.28 ft 3 /(pax ⋅ hr)13.3 ft 3 /(pax ⋅ hr) Cruise Mach Initial Cruise Altitude42000 ft40000 ft42000 ft Cabin Noise60 dB70 dB 65 dB* (will differ among concepts) LTO NOx EmissionsCAEP 6-75%CAEP 6-60%CAEP 6-70%* Cumulative Certification Noise Limits 232 dB274 dB274 dB* Cruise Specific Range0.3 nm/lb0.26 nm/lb Concept 1: 0.29 nm/lb* Concept 2: 0.31 nm/lb* Loading Door Sill Height4 ft5 ft4 ft* Variable Costs$4100/hr*$4300/hr$4100/hr* * Value estimated at current stage in analysis 42

Summary & Next Steps Summary ◦ Two concepts selected for detailed analysis ◦ Sizing improved using component based method and engine model ◦ Early stability and control estimates developed Next Steps ◦ Select final engine classification (GTF or UDF) ◦ Detailed aerodynamic analysis (airfoil selection, etc) ◦ Detailed stability analysis ◦ Refine sizing code 43

Questions and Comments 44