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ANSTINE MATHEW AUGUSTINE (32208101006)ARUN KRISHNAN. U (32208101009)MAHESH. J (32208101029)VETRI SELVAN. S (32208101057)TAMIL VANAN. V (32208101306)

Military aircraft designed to attack ground and sea target by dropping bombs on them.

Strategic bombers are designed for long-range bombing missions against strategic targets to damage enemy nations war effort .

Light bombersLight bombersMedium bombersMedium bombersDive bombersDive bombersFighters bomberFighters bomberGround attack aircraftGround attack aircraftMulti role combat aircraftMulti role combat aircraft

Major type of aircraft designsMajor type of aircraft designs

• Conceptual designConceptual design

• Preliminary designPreliminary design

• Detailed designDetailed design

Conceptual designConceptual design• It depends on what are the major factors for designing the It depends on what are the major factors for designing the

aircraft. aircraft. • (a) Power plant Location: (a) Power plant Location: • The Power plant must be located in the wings. The Power plant must be located in the wings. • (b) Selection of Engine: (b) Selection of Engine: • The engine should be selected according to the power The engine should be selected according to the power

required i.e., thrust required.required i.e., thrust required.• (c) Wing selection: (c) Wing selection: • The selection of wing depends upon the selection of The selection of wing depends upon the selection of • (1) Low wing (1) Low wing • (2) Mid wing (2) Mid wing • (3) High wing (3) High wing - For a bomber the wing is mostly high wing - For a bomber the wing is mostly high wing

configuration and anhedral.configuration and anhedral. - Sweep may be required in order to reduce wave drag.- Sweep may be required in order to reduce wave drag.

2. Preliminary design: 2. Preliminary design:

Preliminary is based upon number of factors like Preliminary is based upon number of factors like Loitering.Loitering.

3. Detailed design: 3. Detailed design: In the detailed design considers each & every rivets, bolts, In the detailed design considers each & every rivets, bolts, paints etc. In this design the connection & allocations are paints etc. In this design the connection & allocations are made. made.

To design a bomber aircraftRange of 20000 km & must carry 75000 kg+ of bombs &

missiles.At supersonic & subsonic regimesTo operate at regional bases with low cost of operation &

maintenanceThe aircraft must also be capable of single pilot operation

scenario.Due to long range pilot work load must be reducedThe aircraft must be all weather , all terrain operation capable

including the airbase.To take up a load factor +8g to +7.5g to -3.5g.

• Collect data of existing aircraft of similar purpose i.e., bomber.

• The basic factors of aircrafts performance viz. Weight, Cruise velocity ,Range ,Wing area & Engine thrust.

• The performance data of various bomber aircraft with payload capacity between 5000 & 56600 kg was collected.

• Mirage IIIE• Mirage IVA• F-111F• F-111F swept• Tu-22R• Tu-85/1• YB-60• B-2A etc

Preferred Configuration:Preferred Configuration:

From ComparisonFrom Comparison Parameters• Max takeoff weight (kg)• Thrust to weight ratio• Aspect ratio• Wing loading (N/sq.m)• Span to height ratio• Span to length ratio• Combat radius (km)• Pay load capacity (kmph)• Max Speed (kmph)• Service ceiling (m)• Max Speed (m/s)

Values• 500000• 0.28• 8.4• 7848• 5• 1.5• 5000• 75000• 1000• 15000• 277.77

General rough estimateGeneral rough estimate

Mass Fraction

Payload 0.15

Fuel 0.45

Structure 0.32

Power plant 0.07

Fixed equipments 0.01

Total 1.00

Redefined Mass EstimationRedefined Mass Estimation

2’

 

 

3’

 

 

5’

 

 

4’

 

 

6’

 

 

7’

 

 

8’

 

 

9’

 

 

10’

 

 

0

 

 

1

 

R

 

3

 

2

 

 

h

 

10000 km

1000 km

1000 km

9000 km

1/2 hr

Mission profile for Strategic bombingMission profile for Strategic bombing

Analysis of mission profileAnalysis of mission profileTSFC values for Bomber

Cruise Loiter

0.5 0.4

Comparative data of EnginesComparative data of Engines

Engine SelectionEngine SelectionName of the Engine GP-7000

Manufacturer Engine Alliance

Type Turbofan 2 Shaft

Length (m) 4.74

Diameter (m) 3.16

Wet weight (kg) 6800

Dry Weight (kg) 6712

Maximum Thrust (kN) 363

Overall Pressure Ratio 43.9

Thrust to Weight Ratio 4.73

Fan Diameter (m) 2.95

The above engine has been selected from a list of engines.The above engine has been selected from a list of engines.

Redefined Thrust to weight ratioRedefined Thrust to weight ratio

AIRFOIL SELECTION

content

• Airfoil nomenclature• Lift coefficient • Drag coefficient• Types of airfoil• Formula used• Airfoil

AIRFOIL NOMENCLATUREThe cross-section shape obtained by the intersection of wing with the perpendicular plane is called airfoil. The major design feature of an airfoil is the mean chamber line ,which is the locus of points halfway between the upper and lower surface ,as measured perpendicular to mean chamber line itself .The most forward and rearward points of the mean chamber line are the leading and trailing edge respectively.

THE FORWARD AND REARWARD POINTS OF THE MEAN CAMBER LINE ARE THE LEADING AND TRAILING EDGES.

CHORD LINETHE STRAIGHT LINE CONNECTING THE LEADING & TRAILING EDGES.

MEAN CAMBER LINETHE LINE BETWEEN UPPER &LOWER SURFACES.

CHAMBER MAXIMUM DISTANCE BETWEET THE MEAN CAMBER LINE & THE CHORD LINE.

LIFT COEFFICIENT

• The lift coefficient (CL or CZ) is a dimensionless coefficient that relates the lift generated by an aerodynamic body such as a wing or complete aircraft, the dynamic pressure of the fluid flow around the body, and a reference area associated with the body. It is also used to refer to the aerodynamic lift characteristics of a 2D airfoil section, whereby the reference "area" is taken as the airfoil chord. It may also be described as the ratio of lift pressure to dynamic

Drag Co-efficient:

The drag coefficient (commonly denoted as Cd, Cx or Cw) is a dimensionless quantity that is used to quantify

the drag or resistance of an object in a fluid environment such as air or water. It is used in the drag equation, where a lower drag coefficient indicates the

object will have less aerodynamic or hydrodynamic drag. The drag coefficient is always associated with a

particular surface area.

TYPES OF AIRFOIL

• CHAMBERED AIRFOIL

• SYMMETERICAL AIRFOIL

CHAMBERED AIRFOIL

• It is also called as unsymmetrical airfoil .• Upper surface of the airfoil is not equal to

lower surface.

SYMMETRICAL AIRFOIL:

• Surface above the chord line and below the chord line are equal.

FORMULA USED

FORMULA USED

6. Airfoil selection and Wing Geometry estimates

• Main Parameter Selection:• Wing Loading:

Thickness based Reynolds Number

Flap selection:Flap selection:

Wing geometry

Critical Mach number for the airfoil

LANDING GEAR

TYRE SELECTIONTYRE SELECTION

• Load DistributionLoad Distribution • Typical load of aircraft while landing ;WTypical load of aircraft while landing ;WLL=W=WT T -O.8W-O.8WFF

• While aborting mission ; WWhile aborting mission ; WLL=W=WTT-O.1W-O.1WFF

• During static condition ; WDuring static condition ; WLL=W=WTT

CONTACT AREA

• Ww=Ap x P

• Ap=2.3 √ dwww(dw/2-Rt)

• Rt=(dw/2-Ap/(2.3 √dwww))

*RUN WAY LOADINGRunway loading=load on each wheel/area of contact

Runway Loading

DIMENSIONAL ESTIMATES

• Span to height ratio=b/ha ≈5

• Span to length ratio=b/la ≈ 1.5

• CONFIGARATION OF TAIL

• Horizontal stabilizer

• Horizontal stabilizer sizing 15% of wing area;sh/s=0.15

• Vertical stabilizer geometry

• Vertical stabilizer sizing 9% of wing area ;sv/s=0.09

Configuration of tail

Airfoil NACA 0012

• PREPARATION OF LAY OUT

• Wing location and C.G estimation Wfuselage X fuselage + W wing (X +X wing) =

(Wfuselage+Wwing) (X+Xfinal)

• Where X is the location of wing root L.E from the nose fuselage and Xfinal is the reaction of cg from the L.E at root

• X final=0.35(Xcr - Xct)

Wing Detail for cg estimation

Three views of Aircraft

Front view

Side view

DRAG POLAR

• Drag equation for entire Aircraft:Cd=Cdwing+Cdothers+KCL^2

• *wetted surface area

• Fuselage =Wfuselage*hfuselage

• Engine =4* π/4d^2

• Nose landing gear=dw*Ww*4

• Main landing gear=dw*Ww*12

• Main landing gear=dw*Ww*8

• Flap=Lflap * Wflap

• Take off performance =Cdpermanent+CdLG+Cdflap+Cdwing

• Landing performance=Cdpermanent+CdLG+Cdflap+Cd wing

• Cruise performance=Cdpermanent+Cdwing

Drag polarDrag polar

Lift to Drag RatioLift to Drag Ratio

Performance CalculationsPerformance Calculations• Thrust required and Thrust available analysis:• W1= 25% of Fuel and 100 % of Payload

• W1= 3185533.292 N

• W2= 50% of Fuel and 100 % of Payload

• W2= 3784962.23 N

• W3= 75% of Fuel and 100 % of Payload

• W3= 4384391.173 N

Thrust scenarios at Sea level for different Thrust scenarios at Sea level for different weightsweights

Thrust scenarios at 11 km altitude for different weightsThrust scenarios at 11 km altitude for different weights

Thrust scenarios at 25 km for different weightsThrust scenarios at 25 km for different weights