Quote:
Originally Posted by kach22i
Interesting points, lots to think about. The whole in the air the body leaves is important, but so are the air vectors releasing from the body.
Would the Corvette be part of the Bluff Body family? It certainly is not teardrop shaped beyond the canopy.
Some of the reoccurring issues we have in the forum is that only the side view gets compared to the template, no part of the top view is included, and little other 3D analysis.
I could do a template overlay on the stock and AeroWagen version, and include both side profile and top views, I could even attempt to toss in a cross section at the 3/4 mark.
However I'm not convinced it would prove much, and that full scale testing is the only alternative when splitting hairs as fine as this.
EDIT:
The difference between "b" and "c" is a surprise to me.
Alfa img - Showing > Lift Coefficient of Shapes
There is a chart floating around the forum which shows Bluff Body lengths or perhaps Semi-Truck lengths with small differences in relation to Cd. If I stumble across it in the next few days I will post it here. |
The drag coefficients presented are dubious and not representative of actual drag coefficients.
I suspect that they're deleting skin friction and presenting only pressure drag,as Mair did in his boat-tail research.
No.I finally caught it.These are volumetric-based Cds from fuselage,airship, and submarine hull research.
There also surface-area-based Cds.
We need frontal area-based Cds.
No 3-D streamline body of revolution can have a frontal-area-based Cd below 0.04,in free flight,away from ground effect.