Team 1 SDR Presentation 03/04/10 - College of Engineering · 2010. 3. 4. · SDR Presentation 03/04/10 Alex Mondal Beth Grilliot Brien Piersol Heath Cheung Jason ... Generated Designs

Team 1

SDR Presentation

03/04/10

Alex Mondal

Beth Grilliot

Brien Piersol

Heath Cheung

Jason Liu

Jeff Cohen

Jeremy Wightman

Kit Fransen

Lauren Hansen

Nick Walls

Ryan Foley

Tim Fechner

March 4, 2010 AAE 451 Spring 2010 1

Outline• Review Mission

• Aircraft Concepts Selection

• Advanced Technologies

• Constraint Analysis

• Sizing

• Propulsion Systems

• Control Estimates

• Summary of Aircraft Concepts


Mission Statement

Design Mission

Typical Operating Mission

Major Design Requirements


Mission Statement• To Design A Long Range (12-19 passengers),

Environmentally Friendly Business Jet

– Range of 7,100 Nautical Miles (Still Air Range)

– Cruise Altitude above 42,000 Feet

– Cruise Speed between 0.84 and 0.9 Mach

• Environmentally Friendly

– Reduction of Noise

– Reduction of Emissions

– Increase in Recyclable Build Materials

– Increase in Fuel Efficiency

– NASA N+2


Design Mission• 12-19 Passengers, Plus Crew (4)

• Cruise Speed at 0.85 Mach

• Take Off Field Length: 4,700 - 5,200 Feet

• Landing Distance: 2,500 - 3,000 Feet


Typical Operating Mission• 6-8 Passengers, Plus Crew (3)

• Range of 2,500 Nautical Miles

- New York to Los Angeles: 2,139 nmi

Major Design Requirements• Fuel Weight

• Empty Weight

• Cruise Speed

• Range

• Cabin Height

• Cabin Volume

• Take-off Distance

• Cumulative Noise Level

• Sill Height


Aircraft Concept Selection

Generated Designs

Preliminary Designs & Layouts


Brainstorming Concepts


Engineering Judgement• Manufacturing Cost

• Stability

• Practicality

• Appearance

• Noise


Summary of Aircraft Concepts

Layouts and Isometric Views

Compliance Matrix

March 4, 2010 AAE 451 Spring 2010 10

Back Swept Wing with Canards

AAE 451 Spring 2010March 4, 2010 11

Canard provides lift and control

Wings pushed back to improve stability

Fuselage mounted engines to reduce yaw moment

Forward Swept Wing with Canards


Forward Swept Wing reduces TO

ground rollMid-wing to avoid reduced

effective dihedral

Wing mounted engines to improve stability

Wing and Tube Configurations

March 4, 2010 AAE 451 Spring 2010 13

16 passengers

12 passengers

Blended Wing Body


Entire aircraft as lifting surface Reduces boundary

layer ingestion

Combined control surfaces

Blended Wing Body

March 4, 2010 AAE 451 Spring 2010 15

16 passengers

18 passengers


* Values are found from Historical Data

Advanced and Unconventional

Technologies Under Consideration

Blended Wing Body

Alternate Wing Geometry

Propfan

March 4, 2010 AAE 451 Spring 2010 17

Canards• Pros

– Additional lift

– Reduced takeoff and landing

distance

– Natural AOA limiting

– Increased cabin area

– Lower trim drag

March 4, 2010 AAE 451 Spring 2010 18

Source: Rutan, 2005

Source: Beechcraft, 2005

Canards• Cons

– Higher induced drag

– Long moment arm for wing

– Sensitive to design

– Conflict between max CL

and efficiency

March 4, 2010 AAE 451 Spring 2010 19

Source: Gyroflug, 2005

Source: Boeing, 2007

Forward Swept Wings• Pros

– Less wing sweep needed

compared to BSW (≈8°)

– Stalls first at root

– Reduced takeoff distance

– Reduced downwash

March 4, 2010 AAE 451 Spring 2010 20

Source: Hepperle, 2008Source: Hepperle, 2008

Forward Swept Wings• Cons

– Aeroelastic instability

– Aft wings increase moment

about CG

– Fuel location

• Possible Solutions

– Aeroelastic tailoring

– Canards

– Composite Materials

March 4, 2010 AAE 451 Spring 2010 21

Source: Hansajet, 2007

Source: Hepperle, 2008

Blended Wing Body• Pros

– 10-20 dB noise reduction

– 15% OEW reduction

– 15% thrust reduction

– 25% less fuel burn

– 15% L/D increase

March 4, 2010 AAE 451 Spring 2010 22

Source: Liebeck R., 2002

Source: Liebeck R., 2002

Blended Wing Body• Cons

– Higher floor angle on

takeoff and landing

– Composite materials

required for centerbody

– Fewer windows

– Complexity of

aerodynamic design

March 4, 2010 AAE 451 Spring 2010 23

Source: Boeing, 2004

Propfan Engine• Still looking for more information

• Cabin noise and vibration is a concern

• Could greatly reduce fuel costs

• Around 30% increased fuel efficiency

March 4, 2010 AAE 451 Spring 2010 24

Source: NATOSource: NATO

Constraint Analysis & Diagrams

Performance Constraints

Basic Assumptions

Constraint Diagrams

March 4, 2010 AAE 451 Spring 2010 25

Updates Since SRR• Three New Designs

– Back Swept Wing Aircraft

– Forward Swept Wing Aircraft

– Blended Wing Body Aircraft

• More Accurate Assumptions of Performance Values

– Changes for Back Swept Wing Design:

– New Constraint Diagrams for the FSW and BWB Aircraft

March 4, 2010 26AAE 451 Spring 2010

• Aspect Ratio

• Induced Drag Coefficient

• CL Take Off

• CL Landing

• Take-Off Distance

• Landing Distance

Major Performance Constraints• Top of Climb

– Drag of Aircraft

– Aspect Ratio

• Second Segment Climb

– CL Max for Take-Off

– Aspect Ratio

– Drag of Aircraft

• Landing Ground Roll

– CL Max for Landing

– Landing Distance

March 4, 2010 AAE 451 Spring 2010 27

Back Swept Wing Basic Assumptions• Technology Factors:

Canards for

Increased Lift; Rear

Aft Mounted Wing for

Decreased Drag

March 4, 2010 AAE 451 Spring 2010 28

Major Constraints Assumed Values

CL Max 1.12 for Take-Off; 1.3 for Land

L/D (max) 18.58

Empty Weight Fraction ~0.5 to ~0.54

Engine Lapse Rate/SFC 0.45

Parasite Drag (CD0) 0.02

Oswald Efficiency 0.8

Flight Velocities Cruise: 0.85 M; Take-Off: 149 ktas; Landing: 130 ktas; Stall: 100 ktas

Aspect Ratio 8.2

Take-Off Ground Roll 4,300 ft

Landing Ground Roll 3,000 ft

Technology Factors: Canards increase Induced Drag but Reduce Trim Drag

Back Swept Wing with Canards

March 4, 2010 AAE 451 Spring 2010 29

TSL/W0 = 0.35W0/S = 68 lb/ft20

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

40 50 60 70 80 90 100 110 120

TS

L/W

0

W0/S [lb/ft2]

Top of Climb (1g Steady, Level Flight, M = 0.85 @ h=42K, Service Ceiling)

Subsonic 2.5g Manuever, 250kts @ h =10K

Takeoff Ground Roll 4,300 ft @ h = 5K, +15° Hot Day

Landing Ground Roll 3,000 ft @ h = 5K, +15° Hot Day

Second Segment Climb Gradient Above h = 5K, +15°Hot Day

Forward Swept Wing Basic Assumptions

• Technology Factors: Lower Take-Off Distance; Higher Angle of Attack Without Stall




L/D (max) 20






Aspect Ratio 8.2



Forward Swept Wing with Canards


TSL/W0 = 0.33W0/S = 75 lb/ft2

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

40 50 60 70 80 90 100 110 120

TS

L/W

0

W0/S [lb/ft2]






BWB Basic Assumptions

• Technology Factors: Fuselage is Lifting Body; Lower Drag




L/D (max) 20






Aspect Ratio 7.8



Blended Wing Body


TSL/W0 = 0.32W0/S = 60 lb/ft20

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

40 50 60 70 80 90 100 110 120

TS

L/W

0

W0/S [lb/ft2]






Trade Studies• Trade Studies are Ongoing

• Research Indicates Trade-Offs

– Swept Back with Canard Design:

• Lower Drag and Increased Lift than Conventionally Designed

Aircraft

– Forward Swept with Canard Design:

• Increased L/D and Decreased Take-Off/Landing Distance

– Blended Wing Body Design:

• Lower Drag on Lifting Body Surface

March 4, 2010 AAE 451 Spring 2010 34

Sizing Studies

Current Sizing Approach

Basic Assumptions

35March 4, 2010 AAE 451 Spring 2010

Mission

• Range: 7,100 nmi

• Capacity: 19 passengers @ 225 lbf/person

• Typical Operating Mission: 10 passengers

• Max Mach: 0.9

• Cruise Mach: 0.85

TaxiTake off

Climb

Cruise

Loiter

Missed Approach

Land

Cruise to Alternate

Loiter

Land

2nd Climb


Process• Only swept back with canard design included in

main sizing code

• Use constraint diagram for initial parameters

– Wing loading: 68 lb/ft2

– TSL/W0 : 0.35

• Choose range, passenger payload, and crew

weight

• Determine segment weights from equations


Process Continued• Known variables passed

• Gross weight guessed

• Fuel weight loss predicted from drag and TSFC

of engine

• Empty weight fraction determined through a

function from “Introduction to Design: A

Conceptual Approach”

• Entire code iterated until gross weight converges


Segment Weight Fraction• Taxi & takeoff weight fraction: 0.97

• Climb determined through equation

• Loiter weight fraction predicted from equation

• Landing weight fraction: 0.995

• Same for detour segment weight fractions

• Values and equations Determined from

“Introduction to Design: A Conceptual Approach”


Process Visualization


Drag Prediction• Includes parasitic and induced drag

• Parasitic drag determined summing component

drag: fuselage, wing, canard, engine nacelle,

and H & V tails

• Induced drag uses horseshoe vorticies

– Inaccurate at this time


TSFC Prediction• Currently only have data for 50,000 lbf and

5,000 lbf thrust at SL engines

• Given drag, altitude, and Mach a function

determines TSFC for both engines

– At cruise thrust equals drag

• Given maximum thrust at SL at a given iteration,

an effective TSFC determined through linear

interpolation

– Thrust at sea level determined TSL/W0 = constant


Weight Prediction BSW• Current prediction includes the use of drag and

TSFC for cruise segments

• Gross Weight: 96,000 lbf

• Empty Weight: 55,000 lbf

• Fuel Weight: 39,000 lbf

• Empty Weight fraction: 0.53

• Fuel Weight fraction: 0.41


Weight Prediction FSW• Determined by summing up component weights:

avionics, wing, canard, and fuselage

• Added onto gross weight of BSW concept

• Gross Weight estimate: 99,000 lbf


Weight Prediction BWB• Determined using equations for BWB “Aircraft

Design: A Conceptual Approach” and a NASA

study on BWB*

• NASA supercritical airfoils 0518 and 1010 used

for fuselage and wing structure

• Gross Weight estimate: 87,000 lbf

• Empty Weight estimate: 54,000 lbf

• Fuel Weight fraction: 0.38

* A Sizing Methodology for the Conceptual Design of Blended-Wing-Body Transports by Kevin Bradley of George Washington University


Future Goals• Incorporate the other a/c designs into code

• Predict drag more accurately

• Calculate fuel burn during loiter and climb

segments

• Determine a better method determine effective

TSFC


Propulsion Methodology

Concept Description

Planned Approach

Technology Factors

March 4, 2010 AAE 451 Spring 2010 47

Engine concept description • Provide around 17,000 lbs of thrust

• Engine Concepts:

March 4, 2010 AAE 451 Spring 2010 48

Engine Type Constraint on usage

Low-Bypass Turbofan Satisfies All Constraints

High-Bypass Turbofan (β<5) Satisfies All Constraints

High-Bypass Turbofan (β>5) Size

Turbojet Thrust

Propfan Noise, High altitude data

Turboprop Speed

Ramjet/Scramjet Speed

Engine concept description • Engine of choice is a high-bypass turbofan

• Current Baseline Engine Specifications

March 4, 2010 AAE 451 Spring 2010 49

Source: Rolls Royce

Rolls Royce BR710

Thrust 20,000 (lbf)

SFC (at SL) 0.39 (lbm/hr)/lbf

Dry Weight 3520 lbs

Bypass Ratio 4.2

Planned approach • Resize the baseline engine in order to obtain

values for thrust and size that fit the design

requirements.

• Engineering Model

March 4, 2010 AAE 451 Spring 2010 50

Source: NATO

Technology Factors• Weight reduction

• Efficiency

• Alternative Fuels

• Propfan / Improved turbojet

– Currently not enough data to support Propfan usage

– Turbojets operate up to 14,000 lbs of thrust

March 4, 2010 AAE 451 Spring 2010 51

Initial Stability

Center of Gravity

Control Stability

March 4, 2010 AAE 451 Spring 2010 52

Stability Process• Derived the Component Weights

• Found locations where Weight would be focused

• Center of Gravity = (Weight Location)

Weight

• Static Margin = Aero. Center – Center of Gravity

March 4, 2010 AAE 451 Spring 2010 53

Back Swept Wing Stability• Total Length = 110 ft

• CG located at 58% of Length

• CG = 70 ft from Nose

• AC = 75 ft from Nose

• Static Margin = 5.13%

March 4, 2010 AAE 451 Spring 2010 54

Current CG

Forward Swept Wing Stability• Total Length = 110 ft





March 4, 2010 AAE 451 Spring 2010 55

Current CG

Blended Wing Body Stability• Total Length = 87.5 ft





March 4, 2010 AAE 451 Spring 2010 56

Current CG

Next Steps

March 4, 2010 AAE 451 Spring 2010 57

Next Steps• Finalize Sizing Code

• Refine Drag Analysis

• Refine Component Weights

• Component Sizing and Location

• Update CAD model

March 4, 2010 AAE 451 Spring 2010 58

Team 1

SDR Presentation

03/04/10

Alex Mondal

Beth Grilliot

Brien Piersol

Heath Cheung

Jason Liu

Jeff Cohen

Jeremy Wightman

Kit Fransen

Lauren Hansen

Nick Walls

Ryan Foley

Tim Fechner

March 4, 2010 AAE 451 Spring 2010 59

Documents

Team 1 SDR Presentation 03/04/10 - College of Engineering · 2010. 3. 4. · SDR Presentation 03/04/10 Alex Mondal Beth Grilliot Brien Piersol Heath Cheung Jason ... Generated Designs