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Old 10-21-2013, 05:37 PM   #19 (permalink)
aerohead
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Quote:
Originally Posted by freebeard View Post
That's quite a jump in Cd. Assume 5-7 cylinders, that's 2 1/2 to 3 1/2 times the frontal area of 2 tandem cylinders, twice. So 0.22 becomes 0.07 increase?

That's not so bad and where the Cub has a narrow cabin. the eco-lakester would have the cylinders at the stagnation point of a bluff body with 10:1 blister recesses to capture, channel and reattach the turbulence.

I'm going out to the country to work on the VLVW but I'm starting to think that everything it needs—powertrain, wheels/tires and roll cage would get better results in a purpose-built body.
I wouldn't know how to proceed without doing the same logic.Just taking a percentage of the disruption.
If a streamlined forced-air duct covered the heads,fed from a ram-air inlet the 'blisters' could have as low as Cd 0.10 according to one of Hoerner's armament turret data.
Adding the ideal canopy to the fuselage adds 0.007 to the overall drag of a L/D= 8.5 Cd 0.082 fuselage.It looks like the heads could have a very minor impact.
You'd have two very small 'canopies'.
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