ADP Report

8/10/2019 ADP Report

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SATHYABAMA UNIVERSITY(Established under section 3 of UGC Act, 1956)

Jeppiaar Nagar, Rajiv Gandhi Salai,Chennai 600119, Tamilnadu.

Report on

AIRCRAFT DESIGN PROJECT

Title

SUBMITTED BY:


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ACKNOWLEDGEMENT

I would like to extend my heartfelt thanks to Prof.BSMAUGUSTINE (Head of Aeronautical Department) for giving me his able supportand encouragement. At this occasion I must emphasis the point that this DESIGNPROJECT would have not been possible without the highly informative andvaluable guidance by Mr. Churchil , whose vast knowledge and experience hadmade us to go about this project with ease. We have great pleasure in expressingmy sincere whole hearted thanks to him.

It is worth mentioning about my team mates, friends andcolleagues of aeronautical department, for extending their kind help whenever thenecessity was in demand; I think one and all that have directly or indirectly helpedme in making this design project a great success.


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ABBREVIATION

- Density of air

- Dynamic viscosity

- Taper ratio

AR - Aspect ratio

b - Wing spanS - Wing area

Swet - Wetted area

Sref - Reference area

C - Chord of the airfoil

Croot - Chord at rootC tip - Chord at tip

CD - Drag Co-efficient

CL - Lift Co-efficient

D - Drag

L - Lift

E - Endurance

g - Acceleration due to gravity

M - Mach number of aircraft


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R - Range

- Climb Angle

T - Thrust

R e - Reynolds number

ROC - Rate of climb

SL - Landing distance

STO - Take off distance

VCruise - Velocity at cruise

Vstall - Velocity at stall

WCrew - Crew weight

We - Empty weight of aircraft

WF - Weight of fuel

W payload - Payload of aircraft

W0 - Overall weight of aircraft

WL - Wing loading


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CONTENT

Expt .No .

Experiments Page no .

1. Abstract

2. Plots

3. Weight Estimation

4. Aerodynamic Design

5. Wing and Fuselage design

6. Performance characteristics

7. 3 View Diagram

8. Design of V n Diagram

9. Conclusion

10. Bibliography


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ABSTRACT

The purpose of our design project was to design a 200 seater passengermedium range international aircraft by comparing the data and specifications of

present aircrafts in this category. Performance characteristics calculations have also

been performed. Necessary graphs have also been plotted from where certainvalues where deduced. The aircraft possess a low wing, tricycle landing gear and aconventional tail arrangement.


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COM PARATI VE DATA SH EET

Name ofthe aircraft

No ofseats

Wingspan(m)

Wingarea(m 2 )

Aspect ratio Serviceceiling(m)

MacdonnellDouglasMD-90

172 32.87 437.1 13.2 12802

Boeing 727 189 32.9 481.01 14.6 10700

Boeing 757 200 38.05 11.25 4.76 12800Boeing 767 181 47.6 283.3 5.95 12200Boeing 767-

300218 47.6 283.3 5.95 12527

Boeing 787 210 60.1 958.23 15.9 13100Boeing 717 117 28.47 337.176 11.84 12500Boeing 737 189 35.7 146.013 4 12500

A320 180 24.1 122.6 3.59 12000

A310 240 43.9 219 4.9 12500A321 220 34.1 122.6 3.59 12000A330 250 60.3 361.6 5.99 12527


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Name of theaircraft

Empty fuelweight(kg)

M ax takeoff

weight(kg)

Payload(kg)


35400 43900 172000

Boeing 727 45360 95028 189000

Boeing 757 82380 115680 200000Boeing 767 80130 124880 181000Boeing 767-

30086070 158760 218000

Boeing 787 110000 228000 210000Boeing 717 66406 54900 117000Boeing 737 41413 79010 198000

A320 42600 78000 18000

A310 80142 141974 240000A321 48500 93500 220000A330 180000 230000 250000


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Name of theaircraft

Machnumber

Range Serviceceiling

CruisingSpeed


.76 3860 12802 811

Boeing 727 .85 4450 10700 920Boeing 757 .8 7222 12800 850Boeing 767 .8 5200 12200 851Boeing 767-

300.8 5200 12527 851

Boeing 787 .85 5665 13100 903Boeing 717 .77 3815 12500 811Boeing 737 .785 5650 12500 828

A320 .82 5900 12000 828A310 .801 6800 12500 850A321 .78 5900 12000 828A330 .82 12500 12527 871


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PLOTS


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0

2

4

6

8

10

12

14

16

18

0 2000 4000 6000 8000 10000 12000 14000

A s p e c t r a t i o

Range (m)

Aspect ratio Vs Range


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WEI GH T ESTI M ATI ON

Overall weight of the aircraft includes the crew weight, payload weight,fuel weight and empty weight. The weight of an aircraft will not be constantit will vary according to flight conditions like takeoff, cruising and landing.

The overall weight is given by:-

This equation can be simplified as follows

( ) 1

Now can be estimated by finding the values of and

M ission Profi le

Total number of crew = 8

Assuming weight allotted for one is 100 kg


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= = 8000 N

Total number of passenger = 200

=

= 200000N

= Weight at the end of take off

= Weight at the end of Climb

= Weight at the end of Cruise

= Weight at the end of descent (loiter for 20 minutes) = Weight at the end of landing


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1 st iteration:

F rom Table:

Take off weight fraction = .970

Climb weight fraction =.980

Landing weight fraction = .995 For Cruise Condition:-

Weight fraction calculation formula is : c =

= ./ Breguets range

=

. /

= 0.784

For Endurance condition

Take endurance for 20min i.e. 1200 s

. /

= 0.992


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= (.970) (.985) (.784) (.992) (.995) = 0.74 = (1 )

=

= 0.275Substituting in equation 1

=

= 9, 24,444.44Nnd iteration:

=

=

= 0.465

Substituting in equation 1

=


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= 8, 00,000 N

rd iteration

=

= = 0.47

Substituting in equation 1

=

= 815686.27 N.

For Values of A, C, K Refer the table


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AEROF OI L SEL ECTI ON

An airfoil in many respects is the heart of the airplane. An airfoilgenerates lift by changing the velocity of the air passing over and under itself. The

airfoil angle of attack and /or camber causes the air over the top of the wing totravel faster than the air beneath the wing. Bernoullis equation shows that highervelocities produce lower pressure, so the upper surface of the airfoil tends to be

pulled upward lower than the ambient pressures while the lower surface of theairfoil tends to be pushed upward by higher than ambient pressure. The integrateddifference in pressure between the top and bottom of the airfoil generate the netlifting force.

Types of aerofoil :

a) Symmetric Aerofoil b) Cambered Aerofoil

1) On a symmetric airfoil, the center of pressure lies exactly on one quarter ofthe chord behind the leading edge

2) On a cambered airfoil, the aerodynamic center lies exactly on one quarter ofthe chord behind the leading edge

3) Supersonic airfoils are much more angular in shape and can have a very sharpleading edge, which is very sensitive to angle of attack. A supercritical airfoil


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has its maximum thickness close to the leading edge to have a lot of length toslowly shock the supersonic airfoils have a low camber to reduce dragdivergence. Modern aircraft wings may have different airfoils section alongthe wing span, each one optimized for the conditions in each section of the

wing

In order to select the airfoil we have to find and Re number

To find

During stall L = W

=

= 1.25

=


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Lif t :

L = 130.537 KN.

Drag:

= 0.03 + 0.056

C d = 0.0865

Now,

D = 9033.19 N

D = 9.03319 KN.


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WI NG DESI GN

After the final weight estimation of the aircraft, the primary componentof the aircraft to be designed is the wing. The wing weight and the liftingcapabilities are in general, a function of the thickness of the aerofoil section that isused in the wing structure. The first step towards designing the wing is thethickness estimation

1. Position of the wing:The location of the wing in the fuselage (along the vertical axis)is very important. Each configuration hasd its own advantages but in

this design, the low wing offers advantages such asa. Uninterrupted passengers cabin.

b. Placement of landing gear in the wing structure itself.c. Location of the engine on a low wing makes engine overhaul easier.d. Landing gear usually becomes high in such wing configurations and

therefore, provides greater ground clearance.e. Low wing affects the flow over the horizontal tail to minimum extent


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Design character istics:

m

S = 200 m 2

C = 3.09 m

b = 34 m

AR = 11

= 0.45

Design Calculations:

1. Chord length at root, , - = * + = 8.11 m

2. Chord length at tip =


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= 3.649 m

3. Quarter chord line,

= 0.7725 m

4. Mean Aerodynamic chord, = 0 ( )1 = 6.158 m

5. Wing Aerodynamic centre = = 0.25 * 6.158= 1.539 m

6. Distance of aerodynamic centre from fuselage, y`= 0 1 = 7.425 m


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F USEL AGE DESI GN

The fuselage is an aircrafts main body section that holds the crew passengers or cargo. The fuselage also serves to position control and stabilizationsurfaces in specific relationships to lifting surfaces, required for aircraft stabilityand maneuverability. It always streamlined to minimize the drag produced.

Wing location Aerodynamics Consideration:

Mid wing position gives lowest interference drag, especially well forsupersonic aircraft.

Top-mounted wing minimizes trailing vortex drag, especially good for low-speed aircraft.

Low wing gives improved landing gear stowage & more usable flap area.

From the above given locations of wings, the one chosen is the Low wingconfiguration which gives improved landing gear and more usable flap area.


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Seating ar rangements


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Design Calculations:

= 0.85

l = = 40 mFineness ratio, = 8

d = 5 m

= 40.55 m 2

swet = 159.45 m2

Assume length of cone= 4 m

= 2.35 m

Assume length of empennage = 3 m

= 1.8

= 1.66 m


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AI RCRAF T PERF ORM ANCECALCULATIONS

The performance of an aircraft is essentially a statement of its capabilities anda different selection of these normally be specified for the various categories such

as transport, military and light aircraft, even though several common performancefactor will feature in every such selection. For the engineer involved in the creationof a new design, these performance features serve as design criteria or at leastdesirable objectives, whereas late in the design and development stages the salesstaff will quote the performance features as the basis for the commercial strength ofthe emerging aircraft. For either reason the performance will be stated in terms ofquantities such as direct operating cost (DOC), maximum range for various

payloads and fuel loads, cruising speed and airport requirements for landing andtake-off. Here we are going to calculate the thrust, landing distance, take-offdistance, rate of climb, climb angle and endurance.

1) Thrust Calculation:

During level flight

. / . /

. / ./ . / . / 0./ ./ . /1

= 0.05880.7838.33


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=0.3835

Thrust = 0.3835791215.6815

T = 303.4312139 KN

For one Engine,

T = 151.7156069 KN

2) Landing Distance Calculation:

, -

[()]

3) Takeoff Distance Calculation:

[ ( )]


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[)]

= 2354 m

= 2.354 Km

4) Rate Of Climb (ROC):

ROC = Vsin()

ROC = 40.75 m/s

5) Climb Angle ():

. /

6) Endurance (E):

. /


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./


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3-D VI EWS


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V-n DI AGRAM

The v n diagram is a graph portraying load factor velocity for given airplane, along with the constraints on both n and v due to structural

limitations. The v n diagram illustrates some particularly important aspects ofoverall airplane performance.

Load factor aids us in fixing boundaries to an aircraft within which the aircraft isfree to perform and operate. Load factor is dependent on gravity and hence it alsocan be expressed in terms of g. Load factor are assumed and depending in that wehave corresponding velocities and eventually v n plot.

For our calculation, we consider load factors direct proporationality to the squareof velocity. Load factor is given by

Positive load factor indicate that the aircrafts is ascending up.

When n = 1, V = 59 m/s

When n = 2, V = 83.43 m/s

When n = 3, V = 102.19 m/s

When n = 4, V = 118 m/s

Negative load factor are experienced by aircrafts when it descends down.


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When n = -1, V = 59 m/s

When n = -2, V = 83.43 m/s

When the velocity is 0, load factor is also zero.

Plot

From the above values of v and n we have a v n diagram

Load factor n = 1 gives an initial boundary limit and a dive speed of 250 m/s gives

a final boundary limit.

The area exposed by continuous lines in the plot is the regime in which the aircraftis bound to perform an operate. The first vertical line crossing X axis at 59 m/ssets the boundary of minimum speed The second vertical line crossing X axis at 250 m/s sets the boundary of maximum speed


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Thus the aircraft can operate between velocities of 59 m/s and 250 m/s.

CONCLUSION

A detailed study was concluded on the existing 200-240 seat long range business jet aircraft on design, performance, structure, and aerodynamics. A minor parametric analysis was also made from the design perspective. This study enablesus to design an aircraft with contemporary requirements. The preliminary design

process was made with much of a compromise between science and logic. Theknowledge was very much demanding for every member of the team in order to

produce an effective design. This project greatly enable us to apply our wideknowledge of aerospace in the design of aircraft which was very exciting andchallenging and it had let our imagination take flight , right from the start. In this

project we have finally developed a model of the required aircraft after a detailedstudy. This project would be remembered as the most enjoyable part of theacademic work.


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BIBLIOGRAPHY

1) Janes All the World Aircraft 2) Civil Aircraft Design

Lyoyd R. Jenkinson , Paul Simpkin , Darren Rhodes

3) Aircraft Design A Conceptual Approach Daniel P. Raymer

4) Aircraft Design : Synthesis and Analysis Ilan Kroo , Richard Shevell

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