The skin-friction drag coefficient, denoted as Cf, is a dimensionless aerodynamic parameter that quantifies the aerodynamic drag resulting from the frictional resistance between a fluid flow and the surface of an object, such as an airfoil, wing, or body. It is an essential parameter in aerodynamics and fluid dynamics, helping to characterize and analyze the drag forces experienced by objects moving through a fluid medium.Â
- Cf: Skin-friction drag coefficient for the entire object
- x1: Characteristic length of region 1
- c: Chord length of the object
- (Cf,1)laminar: Skin-friction drag coefficient under laminar flow conditions in region 1
- (Cf,c)turbulent: Skin-friction drag coefficient under turbulent flow conditions in the entire chord length
- (Cf,1)turbulent: Skin-friction drag coefficient under turbulent flow conditions in region 1