Re: ^ drag force on an object on an automobile

On Tue, 23 Aug 2005, aguy wrote:

> Suppose there is a block 1 m by 1m by 1m sitting on top of an automobile
> while driving. Is there a way to estimate the additional drag force and
> hence the increased fuel consumption due to this block. I will
> appreciate any help.

Well, I'd just look up the drag coefficient for a cube, and use that as a
first estimate. Should be available in a decent fluid mechanics book, or
via google. Anyway, about 1 for Reynolds numbers over 10^4.

Drag force is drag coefficient * cross-sectional area * density of air *
velocity^2/2.

--
Timo
.