In aerodynamics, form drag, profile drag, or pressure drag, is a component of parasitic drag. The general size and shape of the body is the most important factor in form drag; bodies with a larger apparent cross-section will have a higher drag than thinner bodies. "Clean" designs, or designs that are streamlined and change cross-sectional area gradually are also critical for achieving minimum form drag. Form drag follows the drag equation, meaning that it rises with the square of speed, and thus becomes more important for high speed aircraft. Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ... Parasitic drag is drag caused by moving a solid object through a fluid. ... In fluid dynamics, a streamline is the path that an imaginary massless particle would make if it followed the flow of a fluid in which it was embedded. ... In physics, the drag equation gives the drag experienced by an object moving through a fluid. ...
Formdrag, profile drag, or pressure drag, arises because of the form of the object.
Formdrag follows the drag equation, meaning that it rises with the square of speed, and thus becomes more important for high speed aircraft.
Interference drag is also create by closely spaced parallel surfaces such as the wings of a biplane or triplane, or the facing surfaces of an external load (such as an external fuel tank or weapon) and the fuselage or wing.
The drag force is computed using the coefficient of drag, the fluid density, the projected area of the body or the surface area of the body oriented perpendicular to the fluid flow, and is the relative velocity of the body with respect to the fluid.
Formdrag is always one component of the drag on a body moving relative to a fluid.
Several factors affect the magnitude of formdrag, including the relative velocity of the body with respect to the fluid, the magnitude of the pressure gradient between the front and rear ends of the body, and the size of the surface area that is aligned perpendicular to the flow.