form drag

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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

form drag
Flow over low drag body.
form drag
Flow over body with high form drag.
form drag
Relationship between form drag and speed.
form drag
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 ?
Since parasitic drag increases dramatically with speed, the savings of climbing are most pronounced when flying fast.
In single-rotor helicopters, almost 33% of the total vehicle drag can be caused by the parasitic drag from the hub.
In addition, each engine family gets a unique grille that only allows in the air the engine will need, thus reducing parasitic drag in the engine compartment.
In order to determine the power needed to reach the speed goal of 210 mph at Bonneville, the power at the rear wheels, top speed and aerodynamic and parasitic drag must be determined for the stock truck.
This design also decouples and shuts off the engine when the driver lets off the gas at speeds up to 84 mph in order to eliminate the parasitic drag the engine would place on the driveline.
This fact permits higher fan control temperatures and less fuel-robbing parasitic drag.
Examination of the Duke wreckage revealed the left propeller (failed engine) was not feathered, presenting a large amount of parasitic drag.
The SA-7000 brake features a return spring adjustment bolt for centering the caliper on the disc and a lining retraction spring is designed to eliminate parasitic drag.
The left wing's deflected aileron creates parasitic drag where it didn't exist before while the right wing's induced drag increases, thanks to the greater lift it's generating.
Optional mechanical disconnects are available for the pump drive locations to eliminate parasitic drag when vehicle system hydraulics are not required.