What Is the Aerodynamic Drag Polar (Parabolic) Calculator?
The parabolic drag polar relates the aerodynamic drag coefficient directly to the square of the lift coefficient.
It isolates skin-friction parasite drag from wingtip vortex-induced drag.
How Does the Aerodynamic Drag Polar (Parabolic) Calculator Work?
Calculates induced drag factor k from wing aspect ratio and Oswald span efficiency.
Finds minimum-drag lift coefficient where parasite drag equals induced drag.
Computes maximum aerodynamic efficiency (L/D)max and minimum drag airspeed.
Aerodynamic Drag Polar (Parabolic) Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Standard parabolic drag polar balancing parasite form drag against lift-induced vortex drag.
How to Use the Aerodynamic Drag Polar (Parabolic) Calculator
- Enter zero-lift drag coefficient CD0 from aircraft geometry or wind tunnel tests.
- Enter wing aspect ratio and Oswald efficiency factor e.
- Provide aircraft mass, wing reference area, and flight altitude air density.
Step-by-Step Example Calculation
General Aviation Aircraft Cruise
Input Values:
Understanding Your Result
Maximum L/D defines the best glide angle and maximum unpowered gliding distance.
V_md is the calibrated airspeed for minimum thrust requirement.
Factors That Affect the Result
- Aspect ratio: High aspect ratio wings (sailplanes) dramatically reduce induced drag factor k.
- Aircraft weight: Higher weight increases minimum-drag speed but preserves maximum L/D.
When Should You Use This Calculator?
- Preliminary aircraft sizing, range calculations, and climb performance modeling.
- Determining best glide airspeed in flight manual operations.
Assumptions & Limitations
- Assumes subsonic flight below the critical Mach number where wave drag onset occurs.
- Linear lift curve without boundary layer stall.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard parabolic model provides excellent accuracy for attached subsonic flow regimes.