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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