Hi,
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.
Thanks.
On 2005-08-23 snipped-for-privacy@nospam.hotmail.com said: >Newsgroups: rec.autos.tech,sci.mech.fluids >Hi, >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. >Thanks. If your library has a copy of Sighard Hoerner's _Fluid Dynamic Drag_, the classic in the field, you will find your answers there. The drag will be awful. I'd stick it on a short trailer.
Considering that an upright bicycle on my Honda Civic costs me over
5mpg...Tom Willmon near Mountainair, (mid) New Mexico, USA
..Error reading FAT table. Try skinny one (Y/N)?
Net-Tamer V 1.12.0 - Registered
I do not have Cd values for this, but it strikes me that rotating the block 45 degrees will increase the frontal area, so even if the Cd is not higher, the drag will be. That is assuming it is 1m on all sides, i.e, a 1m cube.
If you are talking about a flat plate, I am not sure but the Cd may be higher if the plate is at some angle to the flow. 90 degrees is high Cd, but may not be the highest. Unfortunately, Cd versus angle curves for a flat plate are not the easiest to find, but I may have the curve somewhere, and will look for it.
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