ASGARD AVIATION SYSTEM DEFINITION

REVIEWLogan WaddellMorgan BuchananErik SusemichelAaron Foster

Craig WikertAdam AtaLi TanMatt Haas

1

2

Outline Mission Statement Major Design Requirements Concept Selection

Overview Pugh’s method

Advanced Technologies Technologies incorporated Impact on sizing

Propulsion Selection Constraint Analysis

Major performance constraints Basic assumptions Constraint diagrams

Sizing Studies Design Mission Current Sizing Approach

Initial center of gravity, stability and control estimates Summary

3

Mission Statement

To design an environmentally responsibleaircraft that sufficiently completes the “N+2” requirements for the NASA green aviation challenge.

4

Major Design Requirements

Noise (dB) 42 dB decrease in noise

NOx Emissions 75% reduction in emissions below CAEP 6

Aircraft Fuel Burn 40% Reduction in Fuel Burn

Airport Field Length 50% shorter distance to takeoff

*

*ERA. (n.d.). Retrieved 2011, from NASA: http://www.aeronautics.nasa.gov/isrp/era/index.htm

5

Design Mission

6

Aircraft Concept Selection

Eight Initial Concepts Pugh’s Method Two Result Concepts

Aircraft Concepts1 2 3

4 5 6

7 8

Pugh’s Method Process

• Eight designs were generated and sketched.• A baseline concept was chosen to be the reference or datum.• Each design was evaluated for each criterion

• Each design was assigned a ‘+’,’-’, or ‘s’ based from the datum.• All criteria was equally weighted.

• The ‘+’,’-’, and ‘s’ were totaled• The two concepts with the most ‘+’ were discussed and chosen• A second Pugh’s method was run with a different concept being the datum.• The results were collected as with the first run.• Two concepts were selected for further investigation.

Pugh’s Method (1st run)

DATUM

DATUM

Pugh’s Method (2nd run)

Concept Selection• Both concepts had best results from Pugh’s Method

•Tube and Wing design with advanced technologies

• Tube and Wing design• “H-tail” with two engines mounted in-

between• Swept back wings• Noise shielding• Technologies

• Winglets• Laminar Flow• Efficient Engine• Composite

2

1

12

Two Class System

Seating4 rows 1st Class34 rows Economy Class250 passengers

Seat Pitch39 inches 1st Class34 inches Economy

Class Seat Width

23 inches 1st Class19 inches Economy

Class

13

One Class System Seating

No First Class (Low Cost Carriers)44 rows Economy

Class303 passengers

14

Economy Class Section View

Fuselage Height = 16.5 feet

Aisle Height = 6.5 feet

Head Room = 5.5 feet

15

1st Class Section View Seat Width = 23

inches

Cargo Area = 5 feet

Advanced TechnologySpiroid WingletsPros:• 6-10% reduction in fuel consumption (GII)• Improved climb gradient• Reduced climb thrust

• 3% derate (737-300), resulting in reduction of the noise footprint by 6.5% and NOx emissions by 5% (blended)

• Reduced cruise thrust • Improved cruise performance

• Direct climb• Good looks

Cons:• Additional weight > 1000lbs• Could distort under loads causing performance loss or aerodynamic problems• Complexity to manufacture• Unknown effects during icing conditions

Aviation Week & Space Technology, August 2, 2010. "Head Turning Tip" by William Garvey, "Inside Business Aviation" column, p60. http://www.b737.org.uk/winglets.htmhttp://www.aviationpartners.com/future.html

17

Composite Materials 100 % Composite Aircraft

Lighter weight and stronger than Aluminum Modeled as 20% reduction in empty weight

Additional Benefits of Composite Materials Corrosion and fatigue benefits Reduce the amount of fasteners needed Composites used in acoustic damping Thermal transfer system Extended laminar flow

Disadvantages High costs Difficult crack detection

*http://www.designnews.com/article/14313-Boeing_787_Dreamliner_Represents_Composites_Revolution.php

*Boeing

18

Advanced TechnologyLanding Gear Fairings Reduces the noise in the mid and high frequency

domain compared to the plain landing gear configuration up to 4.5 dB*

Reduces vortex shedding due to bluff-body nature of nose and main landing gear**

Modeled as increase in empty weight

*Molin, N. (2010). Perforated Fairings for Landing Gear Noise Control. Retrieved from eprints.soton.ac.uk: http://eprints.soton.ac.uk/43011/1/paper_vancouver_noabsolute_small.pdf** Bruner, D. S. (2010). N + 3 Phase I Final Review. NASA ERA (p. 94). Northrop Grumman.

19

Hybrid Laminar Flow Control Active drag reduction technique Applied to wing, tail surfaces, and nacelles

can achieve a 15% drag reduction* Reduces fuel by ~ 5%** Increases cost of maintenance by ~ 2.8%** Increases DOC by ~0.8%** Increase in empty weight

*Clean Sky

*Archambaud, D. A. (2007). Laminar-Turbulent Transition Control. 2.** Joslin, R. D. (1998). Overview of Laminar Flow Control. NASA (p. 18). Langley Research Center.

20

Engine Selection Engine type: Geared Turbofan Gearbox allows fan to run at lower speeds than

compressor and turbine, improving efficiency. Provides 12%-15% improvement in fuel burn

range, 50% NOx emissions reduction, and 20 dB decrease from level 4 noise standards

Courtesy of Tosaka Courtesy of Airliners.net

21

Engine Sizing Approach Using NASA Geared Turbofan data to

approximate baseline performance of engine

Plan to use data to find fuel flow and SFC curve fit predictions as function of Mach #, altitude, and throttle setting

Will need to use adjustment factors to size engine to thrust requirements of aircraft

Also adjustment factors for implemented technologies will also need to be incorporated

22

Engine Sizing cont.

Concept Aircraft MTOW (lbs) # of engines Max SLS Thrust (lbf) Scale Factor

Baseline CS300ER 139,600 2 23,369 n/a

2 H-Tail 273,000 2 45,701 1.96

3 Double Fuselage 300,000 2 50,220 2.15

4 Strut-Based High Wing 280,000 2 46,872 2.01

ሺ𝑻𝑺𝑳𝑺ሻ𝒓𝒖𝒃𝒃𝒆𝒓 = (𝑾𝝋 )𝒓𝒖𝒃𝒃𝒆𝒓 [ሺ𝑻𝑺𝑳𝑺ሻ𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆(𝑾𝝋 )𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆]𝒏𝒆𝒏𝒈𝒊𝒏𝒆 𝑺𝑭= 𝑻𝑺𝑳𝑺

ሺ𝑻𝑺𝑳𝑺ሻ𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆

Compared aircraft concepts to Bombardier C-series airplane that will be powered by Pratt & Whitney GTF engines

23

Technologies for Improvement Orbiting Combustion Nozzle (R-Jet Engineering) Combustor employs rotating blades inside inner casing Uses 25% less fuel and cuts CO2 and NOx emissions

by 75% Reduces size and weight of engine while producing

same thrust

24

Technologies cont. Noise Reduction Technologies

Swept/Leaned StatorsScarf InletChevron Nozzle

Images Courtesy of NASA Research

25

Technologies cont. Liquid Hydrogen Fuel

Provides more energy and reduces fuel weightCombustion of LH2 :

○ H2 + O2 + N2 = H2O + N2 + NOx

○ No CO2 emissions/lower NOx emissionsDrawbacks:

○ Fuel must be stored in cryogenic tank○ Added tank structure could cause fuselage to be

less aerodynamic Jet A LH2

density 840 kg/m^3 67.8 kg/m^3

specific energy 48.2 MJ/kg 143 MJ/kg

autoignition temp 210 C 571 C

26

Constraint Analysis & Diagrams Performance Constraints Basic Assumptions Constraint Diagrams

27

Major Performance Constraint Analysis

top of climb (1g steady, level flight, M = 0.8 @ h=35K, service ceiling)

landing braking ground roll @ h = 5K, +15° hot day

second segment climb gradient above h = 5K, +15° hot day

28

Updates Since SRR Conventional with New Technologies

Parameters SRR SDRAspect Ratio 8 7.8

Parasite Drag 0.01 0.016

CL max 1.9 (take off) 2.3 (land) 1.65 (take off) 1.9 (land)L/D max 3.1 17.2Take-off Ground Roll 3,348 ft 4,500 ftLanding Ground Roll 1,500 ft 2,000 ft

29

Basic Assumption for Concept 1 Conventional with New TechnologiesMajor Constraints AssumptionsAspect Ratio 7.8

Parasite Drag (CD0) 0.016

Engine Lapse Rate/SFC 0.374

Oswald Efficiency Factor 0.8

Flight Velocity Cruise:0.8 M; Take-Off: 145 ktas; Landing: 135 ktas; Stall: 110 ktas

CL max 1.65 (take off) 1.9 (land)

Take-off Ground Roll 4.500 ft

Landing Ground Roll 2,000 ft

L/D max 17.2

We/W0 0.474

Cruise Altitude 35,000 ft

30

Constraint Diagrams for Concept 1

TSL/W0

=0.32

W0/S =106 [lb/ft2]

31

Updates Since SRR Conventional H-tail with Engines

Mounted in Between

Parameters SRR SDRAspect Ratio 8 7.8

Parasite Drag 0.015 0.02

CL max 2 (take off) 2.4 (land) 1.8 (take off) 2 (land)L/D max 4.1 18Take-off Ground Roll 3,000 ft 3,500 ftLanding Ground Roll 1,550 ft 1,700 ft

32

Basic Assumption for Concept 2 Conventional H-tail with Engines Mounted in Between

Major Constraints AssumptionsAspect Ratio 7.8

Parasite Drag (CD0) 0.02

Engine Lapse Rate/SFC 0.374

Oswald Efficiency Factor 0.8

Flight Velocity Cruise:0.8 M; Take-Off: 155 ktas; Landing: 140 ktas; Stall: 110 ktas

CL max 1.8 (take off) 2 (land)

Take-off Ground Roll 3,500 ft

Landing Ground Roll 1,700 ft

L/D max 18

We/W0 0.474

Cruise Altitude 35,000 ft

33

Constraint Diagrams for Concept 2

TSL/W0

=0.35

W0/S =98 [lb/ft2]

34

Trade Studies of Performance Requirements

Trade Studies are ongoing Current Trade-offs

Conventional with New Technologies

Geared Turbofan: Less Fuel Weight vs. More Drags

Hybrid Laminar Flow Control: 12-14% Less Drags vs. 2.8% More Cost

Landing Fairing: Reduce noise vs. More Weight Conventional H-tail with Engines Mounted in Between

Improved Control at Low Airspeed and Taxiing vs. More Drags Smaller Vertical Stabilizer vs. Heavier Horizontal Tail

35

Sizing Code Incorporation Using NASA Geared Turbofan data to

approximate baseline performance of engine

Plan to use data to find fuel flow and SFC curve fit predictions as function of Mach #, altitude, and throttle setting

Will need to use adjustment factors to size engine to thrust requirements of aircraft

Also adjustment factors for implemented technologies will also need to be incorporated

36

Sizing Code Using MATLAB

software, first order method from Raymer

Used several inputs to determine the size of pre-existing aircraft for validation

37

Status of Sizing Code Currently the code calculates

coefficients of lift and drag needed for fuel burn predictions

Future work needed includes the component weight build up

38

Incorporating Drag Drag values affect

the sizing and are necessary in order to predict the takeoff weight

Included in the equation are the parasitic, induced, and wave drag

39

Validation Boeing 767-200ER

Passenger Capacity: 224

Range: 6,545 nmiCrew: 2Cruise Mach: 0.8Max Fuel Capacity:

16,700 gal

40

Validation continued

Actual Prediction % Error

Gross Takeoff Weight

395,000 [lb] 421,170 [lb] 6.63

Empty Weight Fraction

.46684 .45925 1.63

The sizing code predictions are accurate

The error factor for the takeoff weight is:

41

Selected Concept Predictions

Tube and wing with H-Tail

Take Off Gross Weight[lb]

Empty Weight Fraction

Wempty

[lb]Wfuel

[lb]Wpayload

[lb]Wcrew

[lb]

266239 .474 126267 83572 55000 1400

Tube and wing with new technology

Take Off Gross Weight[lb]

Empty Weight Fraction

Wempty

[lb]Wfuel

[lb]Wpayload

[lb]Wcrew

[lb]

269895 .474 127918 85577 55000 1400

L/Dcruise = 17.2, AR = 7.8

L/Dcruise = 16.9, AR = 7.8

42

Center of Gravity, Stability, and Control Estimates

Center of Gravity

Neutral Point

Tube and Wing Tube and Wing aft engines

CG ~ 55% of fuselage CG ~ 70% of fuselage

SM ~10% SM: ~ 5 %

43

Tail Sizing Current Approach

Using Raymer Equations (6.28) and (6.29)

Concept 1 Concept 2Tail area 815 ft2 1100 ft2

Vertical Tail area 660 ft2 600 ft2

Concept 1

•Length: 180’ 180’ 3’’ •Wing Span: 157’ 156’ 1’’•Height: 51’ 51’•Fuselage Height: 17’ 17’ 9’’•Fuselage Width: 16’ 16’ 6’’

Concept 2 767-300

Concept 2

•Length: 180’ 180’ 3’’ •Wing Span: 165’ 156’ 1’’•Height: 45’ 51’•Fuselage Height: 17’ 17’ 9’’•Fuselage Width: 16’ 16’ 6’’

767-300Concept 1

46

Design Requirements

Requirement Unit Target Threshold

Conventional a/c with new

Tech Compliant

conventional a/c with H-

Tail, aft engines

Range naut. miles 4000 3600 3900 Yes 3800 Yes

Payload pax 250 230 250 Yes 250 Yes

Cruise Mach # - 0.8 0.72 0.8 Yes 0.8 Yes

Take Off Ground Roll ft 7000 9000 4500 Yes 3500 Yes

Landing Ground Roll ft 6000 6500 2000 Yes 1700 Yes

Emissions g/kN thrust 15 22 - N/A - N/A

Noise (Cum.) dB -42 -32 - N/A - N/A

Compliance Matrix

47

Next Steps Finalize Sizing Code Complete Component Weights Determine Aircraft details

NoiseCostStability and Control