2007 Focus Front Air Dam

[lunarhighway]

there is something off on your first graph, majorly off

well it's just a graph i got somewhere of the web to illustrate a generic wake as it might come of a flat plate. so i make no claim as to the accuracy of anything pictured

i don't know all that much about aerodynamics, but the main difference i see is the R value i have no idea what that stands for in this graph (reynolds number perhaps?) but it might explain the different numbers

but it doesn't matter all that much, the point i wanted to make is that the fact a flap plate has a large wake is an advantage, as you can have a smaller dam send the air around the larger tire behind it. but if you make it to wide you may actually add drag.

[euromodder]

Originally Posted by d0sitmatr

there is something off on your first graph, majorly off
the first cylinder shows a CD of 1.2, the teardrop and the 2nd cyl shows the same, but then the last cyl shows a CD of 0.6

For the latter cylinder the Reynolds number is 100 times higher, and the air's separation point is well aft of the center / greatest width as seen by the air.

[d0sitmatr]

that still doesnt explain why the variance in air flow, a cylinder is a cylinder (or a circle a circle) which will have the same dynamic affect on the flow pattern.
unless #1/2 are cylinders and #3 is a ball, which of course will have a huge impact on flow.
either way, the teardrop should have the lowest CD on the chart according to the flow pattern itself.

@ lunar, sorry, I didnt mean to imply it was your chart specifically, just that you posted it so as such are responsible for it

[mbrac]

any updates to this? just wandering how it all came out? I have the same car and I'm thinking about doing the same thing. Thanks!