Cruise Flight Characteristics for both Jet and Propeller Aircrafts

This is a GUI program that calculates the cruise flight performance, for both Jet-Engine and Propeller-Engine aircrafts, the performance characteristics include: Maximum Level Flight Speed, Minimum Level Flight Speed, Stall Speed, Speed Corresponding to Minimum Power and Minimum Drag, Lift to Drag Ratio for Minimum Power and Minimum Drag, Lift Coefficient for Minimum Drag and Minimum Power, and finally chart presenting Induced Power and Induced Drag, Zero-Lift Power and Zero-Lift Drag, Total Power and Total Drag, and position of Vmin, Vmax, VDmin, and VPmin.

To run the program you need to insert the following values: Flight Altitude, Reference Area, Airplane Weight, Engine Power or Thrust, Zero-Lift Drag Coefficient CDo, K constant of CL^2 in the drag polar equation, the Maximum Lift Coefficient, and Propulsive efficiency.

The code based on Pamadi[1] and Saarlas[2] equations of performance of jet engine aircraft in cruise flight.

Examples you can try with this program:

[1] A propeller airplane weighs 45000 N and has a reference area S of 31 m2. The drag polar is given by CD = 0.014 + 0.038CL^2, CLmax = 1.5, and the engine power P = 921 KW and propulsive efficiency (Eta) 0.85 . Determine the maximum and minimum speeds in level flight at sea level and at an altitude of 10 Km, and what is the Speed and Minimum Power at the maximum height.

[2] A jet-engine airplane weighs 51 KN and has a reference area S of 26 m2. The drag polar is given by CD = 0.009 + 0.06CL^2, CLmax = 2.05, and the engine thrust T = 31,900 a. Determine the maximum and minimum speeds in level flight at sea level and at an altitude of 9000 m. What is the absolute ceiling of this airplane?

Used Terms:

• L: Lift
• D: Drag
• Em: Maximum E(L/D)
• mp: Minimum power
• Emp: E for Minimum Required Power
• CD0: Zero-Lift Drag Coefficient
• K: Weight of CL^2 in Drag Polar (CD = CD0 + K*CL^2)
• Vmp: Velocity at Minimum Required Power
• CLmp: Lift Coefficient for Minimum Required Power
• eta: Propulsive Efficiency

Program Interfaces:

The Program has three GUIs, as presented in the down pictures, the main interface gives you a Choice to select either Jet-Engine Aircraft or Propeller-Engine Aircraft Performance Analyzer. The second and third interfaces are the Jet-Engine Aircraft analyzer window and Propeller-Engine Aircraft Performance analyzer window themselves.

References:

[1] Bandu N. Pamadi, Performance, Stability, Dynamics, and Control of Airplanes, Second Edition,  at NASA Langley Research Center, Hampton, Virginia.

[2] Maido Saarlas, Aircraft Performance, Department of Aeronautics Engineering at U.S. Naval Academy.