Drag Estimation for a Subsonic Aircraft

In summary, the drawing and the Aircraft Data show the general arrangement and dimensional data on an early version of the English Electric “Canberra” B.1 bomber, powered by two Rolls Royce “Avon” jet engines. The calculation of the zero lift drag (DO) is based on flight at 0.7 Mach No. at 11000 m ISA. The report must be presented as a formal document, neatly typed and properly edited - containing a Summary Sheet, Introduction, Sections, Figures etc., all with page numbers and with a list of references quoted ( and referred to in the text as necessary).
  • #1
geraldx777
4
0
1. Homework Statement
The small scale drawing given in the Annexure shows the general arrangement and dimensional data on an early version of the English Electric “Canberra” B.1 bomber, powered by two Rolls Royce “Avon” jet engines. It was and is an extremely successful aircraft, designed by W E W Petter. It first flew shortly after the end of WW2 and is still in service, well over forty years later.

The drawing and the Aircraft Data will give you most of the information you need, but you may have to do some measuring and make some assumptions. If you do this, give your reasoning.

You are tasked with estimating the zero lift and lift-dependent drags of the aircraft and to present these in the form of a drag polar:-

CD = CDo + k CL 2
Where, k = 1/ ΠAR


with CL from O to 1.0, using the given Reference Wing Area for the coefficients.

You must also estimate the Mach Number at which there is a steep drag rise.

In calculating the zero-lift drag (DO) you should use a Reynolds Number based on flight at 0.7 Mach No. at 11000 m ISA.

Full details of the calculation must be given and it is most important that you state clearly what assumptions you have made and give the references to any data you may have used.

Your report must be presented as a formal document, neatly typed and properly edited - containing a Summary Sheet, Introduction, Sections, Figures etc., all with page numbers and with a list of references quoted ( and referred to in the text as necessary).

You must give full details of your assumptions and calculations, including

a. a breakdown showing the DO / q for each item and the total DO / q (Give the corresponding value of CDo),

b. State the makeup of the drag due to lift factor k in the expression k CL2 ,

c. A plot of the drag polar,

d. State the value of max lift/drag ratio, and the CL, at which it occurs,

e. State what, in your opinion, is the Mach Number at which the drag coefficient begins to rise steeply.

Aircraft Data - English Electric “Canberra” B. 1 JET bomber

1. Wing

Span, wingtip to wingtip 64 ft.
Inner wing, between fuselage & nacelles,
Aerofoil section NACA 64012
Wing chord 18 ft. 6 in
Outer wing, outboard of nacelles,
Aerofoil section NACA 64012 at nacelle side
Wing chord 18 ft. 6 in.
NACA 64009 at wing tip
Wing chord 6 ft. 10 in.

Reference Wing Area, used for the coefficients, 960 sq. ft.
Wing Aspect Ratio, [Spain]2 ÷ [Wing Ref Area] = 4.267


2. Fuselage

Length, nose to tail 65 ft.
Max. Diameter (all sections circular) 6 ft. 6 in.
Canopy length 6 ft.
Canopy frontal area 3.63 sq. ft.
Length of forebody 16 ft. 2 in
Length of parallel body 16 ft.
Length of after body 32 ft. 10 in.
Wetted Area, fuselage and canopy 985 sq. ft.


3. Tail Plane and Elevators

Span, measured along dihedral plane 28 ft.
Chord at centerline (theoretical) 9 ft. 9 in
Chord at tail/body intersection 9 ft. 4 in.
Chord at theoretical tip 3 ft. 6 in.
Dihedral angle 10 degrees
Aerofoil section NACA 64009

4. Fin and Rudder

Height of fin above fuselage 7 ft. 4 on.
Root chord at fuselage 13 ft. 2 in.
Tip chord 5 ft. 6 in.
Aerofoil section NACA 64010

5. Engine Nacelles

Length 23 ft. 2 in
Entry diameter 27 in.
Intake “highlight” diameter 30. 75 in.
Maximum diameter 48. 75 in
Position of max. diam. 10 ft. from the intake nose
Exhaust pipe diameter 24 in.
Wetted area 194 sq. ft. per Nacelle.
 
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  • #2
can someone help me with this question?
 
  • #3
Think you've answered your own question with:

geraldx777 said:
can someone help me with this question?

Operative word been "HELP" and not doing it for you.

Sure you'll get lots of help, once you have a crack at it yourself and post your attempts.
 

FAQ: Drag Estimation for a Subsonic Aircraft

What is drag and why is it important in aircraft design?

Drag is the force that opposes the motion of an aircraft through the air. It is important in aircraft design because it can significantly affect the speed, fuel efficiency, and performance of the aircraft.

How is drag estimated for a subsonic aircraft?

Drag estimation for a subsonic aircraft involves using mathematical equations and aerodynamic principles to calculate the drag forces acting on the aircraft. This includes considering factors such as air density, velocity, and the shape and size of the aircraft.

What are the main sources of drag in a subsonic aircraft?

The main sources of drag in a subsonic aircraft include skin friction drag, which is caused by the friction between the air and the surface of the aircraft, and form drag, which is caused by the shape and size of the aircraft. Other sources include interference drag, induced drag, and wave drag.

How does drag affect the performance of a subsonic aircraft?

Drag can significantly affect the performance of a subsonic aircraft. It can decrease the speed and maneuverability of the aircraft, increase the fuel consumption, and reduce the range and payload capacity. Therefore, minimizing drag is an important consideration in aircraft design.

What are some methods for reducing drag in a subsonic aircraft?

There are several methods for reducing drag in a subsonic aircraft, including using streamlined designs, minimizing protrusions and gaps, using smooth and polished surfaces, and optimizing the shape and size of the aircraft. Other techniques include using winglets, vortex generators, and laminar flow control devices.

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