# form drag

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Related to form drag: Induced drag, Wave drag

## form drag

[′fȯrm ‚drag]
(fluid mechanics)
The drag from all causes resulting from the particular shape of a body relative to its direction of motion, as of fuselage, wing, or nacelle.
At supersonic speed, the drag caused by losses due to shock waves, exclusive of losses due to skin friction.

## form drag

Flow over low drag body.
Flow over body with high form drag.
Relationship between form drag and speed.
Form lines are broken/dotted lines and sketched from visual observations.
A type of parasitic drag. Form drag is caused by the frontal area of the airplane components being exposed to the airstream. Drag is caused by the form or shape of the body and, hence, the name. It can be reduced by streamlining the exposed parts and by area ruling. Also called boundary-layer normal-pressure drag. See also area rule.
References in periodicals archive ?
The form drag results from wave and wake-making, while the skin friction is due to the tangential shear stress on the ship's hull, caused by the fluid flowing over it.
The form drag is a function of the Froude number, ([C.
The Froude number is used to determine the form drag resistance of ships with different lengths and velocities.
the form drag decreases), the length of a ship increases when the speed is constant.
The relative contribution to the total resistance from the form drag and skin friction of a typical naval ship is shown in Fig.
Figure 3 provides an example of a wake (at stern) and wave (along hull) pattern, which is responsible for the form drag, for a model of the KRISO container ship (KCS) with a Froude number of 0.
The form drag and skin friction are the primary resistances responsible for the fuel consumption where only the skin friction is significantly affected by biofouling on the hull surface.
Typically, a flat plate is used when determining skin friction, and a ship model is used when determining the form drag of a specific ship geometry.

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