DESIGN OF THE SUBSONIC PASSENGER AIRCRAFT

ACHUMON R 98308101302

BENADICT BENSIGER S S 98308101016

THIRUMURUGAN S 98308101053

VARKIS NIRMAL L 98308101301

Submitted by

Abstract

The purpose of the project is to design subsonic passenger aircraft.

The aircraft will possess a sweep back low wing, multi-bogey landing gear and a conventional tail arrangement.

It have a wide body configuration to provide sufficient seating capacity.

It must possess turbofan engines to provide the amount of speed, range and fuel economy for the operation.

INTRODUCTION• We propose to design subsonic passenger aircraft.• It’s Mach number 0.8 and altitude 13000m.• Its range will be 13,000km with a full payload.• This will comfortably accommodate from 300-400 passengers.• Maximum take off weight 61600kg.• Other features of the design include swept back wing

configuration with winglets, split type flaps and very light weight structure.

COMPARATIVE STUDY DIMENSION SPECIFICATION

WEIGHT SPECIFICATION

POWERPLANT SPECIFICATION

PERFORMANCE SPECIFICATION

Selection of Main Parameters

Airfoil SelectionNASA SC(2)-0412

Wing ConfigurationSwept back, low wings

Landing Gear SpecificationRetractable multi-bogey type

Location of CG

GRAPHS

Mach number (M) vs Coefficient of Lift (CL)Mach number (M) vs Maximum L/DVelocity (V) vs Weight (W)Velocity (V) vs Wing loading (W/S)Mach number (M) vs Specific fuel consumption

(SFC)Coefficient of Drag (CD) vs Coefficient of Lift (CL)Velocity (V) vs Range (R)Velocity (V) vs Aspect ratio (AR)Velocity (V) vs Altitude (h)Angle of attack (α) vs Coefficient of lift (CL)

Optimum valuesSl. No. Design parameters Values

1 Mach number 0.85

2 Velocity 253.8m/s

3 Coefficient of lift 2.82

4 Coefficient of drag 0.15

5 Maximum L/D 18.4

6 Weight 223,465kg

7 Wing loading 713.4

8 Specific fuel consumption 0.3472

9 Range 13,038km

10 Aspect ratio 8.586

11 Altitude 13,052m

Mission profile

Landing

Glide

Take off

Climb

CruiseLoiter

44 55

22 33

1100

Take-off weight estimationTotal take off weight is divided into fuel weight, weight of crew, weight of payload, and empty weight.

W0 = Wfuel + Wcrew + Wpayload + Wempty

The fuel and empty weights are expressed as,

This can be solved for W0, we get,

Empty weight fraction

Fuel weight fraction

Maximum Take-Off Weight (W0) = 616,000kg.

Weight of the Fuel (Wf) = 210,424kg

Engine selection

Engine : Trent 772B-60 Thrust : 71,100lb Bypass ratio : 5.0 Inlet mass flow : 2030lb/sec Fan diameter : 97.4in Length : 154in

Properties of selected Aerofoil: NASA SC(2)-0412

Properties of aerofoil NASA SC(2)-0412

Thickness 12.00%Camber 1.30%Trailing edge angle 3.6o

Lower flatness 4.00%Leading edge radius 2.30%Max CL 1.177

Max CL angle 15

Max L/D 23.492Max L/D angle 5Stall angle 5Zero-lift angle -2.5

NASA SC(2)-0412

Effect of flap

Coefficient of lift with Angle of attack with and with out flap.

Coefficient of lift with coefficient of drag with and with out flap.

Wing configurationSweep back, low wing is selected for our

design.

THE MAIN WING DESIGN PARAMETERS CAN BE IDENTIFIED UNDER FOUR HEADINGS:

performance requirementsflying qualitiesstructural frameworkinternal volume

Horizontal and vertical tail:

Fuselage mounted tail is used.

The general drag equation is given by,

Calculation of drag

Drag, D= 34936N

Take off distance

The equations to be used to determine the effect of the take-off criterion is shown below:

Take-off distance is 2,700m to 3,200m.

Landing distance

The approximate equation to determine ground run in landing can be rewritten as shown below:

Landing distance is 1,900m to 2,100m.

Center of gravity

Side view

Front view

Top view

Conclusion

Thus we done the design project successfully. Design is a fine blend of science, creativity, presence of mind

and the application of each one of them at the appropriate time. The scientific society always looks for the best product design. This involves the strong fundamentals in science and

mathematics and their skilful applications, which is a tough job endowed upon the designer.

THANK YOU