This document summarizes the conceptual design process for a Boeing 737 aircraft using Raymer Design Software. The student spent 24 hours understanding the software, gathering data, generating a solid model, and presenting results. Key parameters selected were a cruise Mach number of 0.7 for optimal drag and altitude of 35,000 feet for maximum lift-to-drag ratio. Airfoil selection was based on optimal lift coefficient of 1.3 at Mach 0.7. Results from the basic RDS-EZ software matched closely with the more accurate RDS-Student analysis.

1. Conceptual Design of Boeing 737
Using Raymer Design Software v6.3e by Daniel P. Raymer
By
Sandeep Kumar
Masters student in Aerospace Engineering

2. Contents
• Project Cost
• Geometry Data
• Design Layout Module
• RDS-EZ
• Mach Number Selection
• Cruise Altitude Selection
• Airfoil Selection
• Flight Envelope
• RDS-Student
• Comparison of results

3. Number of hours Spent
Understanding the software = 4 hrs
Data Gathering = 8 hrs
Generation of Solid Model = 3 hrs
RDS-EZ = 1 hr
RDS-Student = 4 hrs
Presentation = 4 hrs
Total = 24 hrs
Project Cost
(in terms of Time)

4. Boeing 737 Geometry Data and Parameters
(Source: Boeing website and Ref. 1)

5. Boeing 737 Geometry Data and Parameters
(contd.)
(Source: Boeing website and Ref. 1)

6. Design Layout Module

7. RDS-EZ

8. • Induced Drag factor increases after Mach number = 0.8
• Favorable Mach number range is 0.7 to 0.8
• Parasitic Drag factor increases after Mach number =0.7
• Favorable Mach number range is 0.6 to 0.7
Hence, optimum Mach number is in the neighborhood of 0.7
Mach Number Selection

9. Cruise Altitude Selection
• With increase in altitude, drag force reduces
• Negligible reduction in drag above 30000 ft. at
Mach number 0.7
• L/D ratio decreases with increase in altitude
• Decrease is drastic above 40000 ft.
• L/D maximum at 40000 ft. for Mach number 0.7
Hence, optimum altitude of 35000 ft. is selected with a service ceiling at 41000 ft.

10. Flight level 350
Passenger Load = Total Load – Fuel load
= 82209.5-38629.3
= 43580.2
Max Range = 3115 nm
Hence,
Range/pax = .0715
Cruise Altitude Selection (contd.)

11. Airfoil Selection
• At Mach Number 0.7, L/D increase slightly
with increase in velocity for Cl values between
1.089 to 1.4 (This implies small increment in
velocity increases lift)
(Source: airfoiltools.com)
Cl-α for Boeing 737 Mid-span Airfoil
The Wing is designed such that it has an optimum Cl value of 1.3
• At Mach Number 0.7 L/D increase slightly
with increase in velocity for Cl values
between 1.089 to 1.4

12. Stall
Speed
Top
Speed
Flight
Conditions
Flight Envelope

13. RDS-Student
• More accurate Aerodynamic
analysis was carried out with
actual data and parameters for
Boeing 737-800
• However, the results are very
similar to the RDS-EZ results

14. RDS-EZ RDS-Student
Comparison of the results

15. RDS-EZ RDS-Student

16. RDS-EZ RDS-Student

17. RDS-EZ RDS-Student

18. • Perkins, H. Douglas, Jack Wilson, and Daniel P. Raymer. "An Evaluation of Performance Metrics for High
Efficiency Tube-and-Wing Aircraft Entering Service in 2030 to 2035." (2011)
References