AeronauticalEngineering II

Design of a Two Seat Standard Glider for Maximum Endurance

Dafydd Hayward 1105759Grace Hynd 1086473

Michael Kontou 1120774Jarrod Mutton 1104863

AeronauticalEngineering II

Conceptual Design

• Weight Calculation

• Sensitivity Analysis

• Aircraft Sizing

AeronauticalEngineering II

Conceptual Design – Weight Calculation

1012682Glaser dirks DG-400

990523.6Akaflieg braunshweig SB-12

616400.4Hanle H 101 salto

1067539Akaflieg Karlsruhe AK-5 standard

998.8572Schleicher ASW-20

1100528Akafleig Hannover AFH 24

957594Akaflieg Braunschweig SB-13

649358.6Marske pioneer II

858506Rollanden schnieder LS-1

448.8220Marske monarch

299.2119.9Maupin carbon dragon

448.8234.3Maupin woodstock one

1038.4598.4Schweizer SGS 2-33A

398.2154Advances aviation Sierra

1155517Schempp hirth ventus

Wto (Ibs)We (Ibs)

Data

AeronauticalEngineering II

Conceptual Design – Weight Calculation

Takeoff Weight Calculation

We = 0.566*Wto - 17.649

100

1000

100 1000 10000

Takeoff Weight (Ibs)

Em

pty

Wei

gh

t (I

bs)

AeronauticalEngineering II

Aircraft Take-off Weight

logWto = 0.7861*logWe + 0.8328

2.00

2.20

2.40

2.60

2.80

3.00

3.20

2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90

log (Empty Weight)

log

(Tak

eoff

) W

eig

ht

Conceptual Design – Weight Calculation

AeronauticalEngineering IIConceptual Design – Weight Calculation

0 200 400 600 800 1000 1200 1400 1600 1800 20000

500

1000

1500

2000

2500

3000

Empty Weight (lbs)

Tak

e-O

ff W

eigh

t (lb

s)

Glider Weight Estimation

WTO ≈ 1100lbs

WE ≈ 600lbs

AeronauticalEngineering II

Sensitivity of Take-off Weight to Payload Weight

082.2

]440[11008328.0

])1([

1

1

=×=

−−=∂∂

−

−TOTO

PL

TO WBCDBWW

W

Conceptual Design – Seinsitivity Analysis

AeronauticalEngineering II

Sensitivity of Take-off Weight to Payload Weight

Conceptual Design – Sensitivity Analysis

082.2

]8328.0/)7861.01100log{(log[11008328.0

]/)log{(log[

1

1

=−×=

−=∂∂

−

−

inv

BAWinvBWW

WTOTO

E

TO

AeronauticalEngineering II

Sensitivity of Take-off Weight to Other Parameters

0

0

0

)1(

})1({ 21

=∂

∂

=∂

∂=

∂∂

+=∂∂

∂∂−−=

∂∂ −

y

Wtherefore

y

Mbecause

y

MM

y

Cnow

y

CBWDBCW

y

W

TO

ff

ffres

TOTOTO

Conceptual Design – Sensitivity Analysis

AeronauticalEngineering II

Aircraft Sizing

Matching Diagram

0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80

W/S (psf)

W/h

p

Stall SpeedTake Off DistanceLanding DistanceFAR 23.65 RCFAR 23.65 CGRFAR 23.77 CGRCruise Speed

AeronauticalEngineering II

Configuration Design

• Wing Design Considerations• Control Surface Sizing• Aerofoil Selection• Empennage Configuration• Landing Gear• Material Selection• Weight & Balance Analysis• Stability & Control Analysis

AeronauticalEngineering II

Comparison of Wing Geometries and Take-off Weights for Standard Gliders

0

100

200

300

400

500

600

Wto (kg) WingLoading(kg/m 2̂)

AspectRatio

Wing Area(m 2̂)

Schempp Hirth Ventus

Rollanden SchniederLS-1Schleicher ASW-20

Akaflieg BraunschweigSB-12Glaser Dirks DG-200

SZD 56 Diana PZL

Configuration Design – Wing Design

AeronauticalEngineering IIConfiguration Design – Control Surface Sizing

The calculation for the aileron sizing is shown below:

MAC = 0.74m% MAC = 25%CA = 0.74 x 0.2

= 0.185m

Based on the Aeronautical Engineering II notes the ailerons will extend from 60% to 90% of the wingspan. This relates to a length of 2.25m per aileron.

AeronauticalEngineering IIConfiguration Design – Aerofoil Selection

Comparison of NACA "6 digit" aerofoil at Re 1 000 000 and 3 000

000 (Soaring Australia, 2006)

Comparison of old section and "6 digit" NACA section (Soaring

Australia, 2006)

AeronauticalEngineering IIConfiguration Design – Empennage Configuration

Glider with T-tail Empennage Configuration (Glossary of Glider Parts, 2007)

Horizontal Tail with Elevator (Frati 1946) Directional Stability of Aircraft Showing Side-force Lift (Frati 1946)

AeronauticalEngineering IIConfiguration Design – Empennage Configuration

Vertical tail surface area, SV = (VV × S × MAC) ÷ xV= (0.12 × 10 × 0.74) ÷ 4.2= 0.211 m2

Horizontal tail surface area, SH = (VH × S × MAC) ÷ xH= (1.1 × 10 × 0.74) ÷ 4.4= 1.85 m2

AeronauticalEngineering IIConfiguration Design – Landing Gear

Longitudinal Tip-over Criterion for Taildraggers (Roskam 2004)

Ground Clearance Criteria for Gear Placement (Roskam2004)

AeronauticalEngineering IIConfiguration Design – Landing Gear

Main Gear

Tail Gear

lm lt

lm + lt

WTO

Pt

Pm

NN 17P483P tm ==

AeronauticalEngineering IIConfiguration Design – Landing Gear

2545Pressure, p (psi)

3.45Width, bt (in.)

912Diameter, Dt (in.)

Tail Gear TyreMain Gear Tyre

AeronauticalEngineering IIConfiguration Design – Material Selection

• Composites

• Glass Fibre Reinforced Polymer (GFRP)

• Carbon Fibre Reinforced Polymer (CFRP)

• Aramid Fibre Reinforced Polymer (AFRP)

AeronauticalEngineering IIConfiguration Design – Weight & Balance Analysis

∑

∑

=

== n

ii

n

iii

CG

W

XWX

1

1

243

7.215.1294.677.275.75.21315.35.121243.285.05 ×+×+×+×+×=CGX

∑

∑

=

== n

ii

n

iii

CG

W

YWY

1

1

243

0.115.1275.177.20.25.214.15.1214.105.85 ×+×+×+×+×=CGY

Centre of Gravity PositionThe CG of the aircraft in the x-direction can be found using the following equation:

Equation 3-2: CG position in x-directionTherefore the position of CG in the x-direction is:

The CG of the aircraft in the y-direction can be found using the following equation:

Equation 3-3 CG position in y-directionTherefore the position of CG in the y-direction is:

AeronauticalEngineering IIConfiguration Design – Stability & Control Analysis

Vertical X-Plot

-0.002

-0.0015

-0.001

-0.0005

0

0.0005

0.001

0.0015

0.002

0.0025

0 0.2 0.4 0.6 0.8 1 1.2

Vertical Tail Area m^2

Dir

ecti

on

al S

tab

ility

(d

egre

es^-

1)

AeronauticalEngineering II

Conclusion