# Reference area, in drag coefficient formula

hi

small question

in the drag coefficient formula

for boats and ships, is the reference area, the surface area of the submerged part of the ship/boat?

demson

tiny-tim
Homework Helper
Welcome to PF!

Hi Demson! Welcome to PF!

It depends … see http://en.wikipedia.org/wiki/Drag_coefficient" [Broken] for details
The reference area depends on what type of drag coefficient is being measured. For automobiles and many other objects, the reference area is the frontal area of the vehicle (i.e., the cross-sectional area when viewed from ahead). For example, for a sphere A = π r2 (hence not the surface area = 4 π r2).

For airfoils, the reference area is the chord …

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