The parasite drag coefficient () is a parameter used in aircraft design and aerodynamics to quantify the drag produced by an aircraft when it is in a clean configuration (without flaps or other high-lift devices) and at a specified flight condition (e.g., cruise). It represents the non-lift-dependent drag that opposes the aircraft’s motion through the air.
The formula for calculating the parasite drag coefficient () is as follows:
- is the parasite drag coefficient (dimensionless).
- is the total parasite drag force (in newtons or pounds-force).
- is the air density (in kilograms per cubic meter or slugs per cubic foot).
- is the true airspeed (in meters per second or feet per second).
- is the wing’s reference area (in square meters or square feet).