aero minimums ( just for fun )

[lunarhighway]

high speed trains are fairly aerodynamic, but trucks are another matter, where the cabins are somewhat aerodynamic at best most of this is undone by ticking a box on the back with all 4 corners extending past the cabin, i imagine rounding the front edges of most cargo boxes could already see massive improvements.

it's strange how earodynamic knowlege can exist in one erea of trasport for decades and be so bluntly ignored in another

[Frank Lee]

Originally Posted by theycallmeebryan

Funny thing is, it's still more aerodynamic than most cars on the road today.

I'd wager it suffers higher drag than conventional designs due to trying to push all that accelerated air through that relatively long duct. It could be worse than cars... it'd be interesting to know the Cd.

[lunarhighway]

wiki says

The Stipa-Caproni proved to be noticeably quieter than conventional aircraft of the time. Unfortunately, the "intubed propeller" design also induced so much aerodynamic drag that the benefits in engine efficiency were cancelled out, and the aircraft's top speed proved to be only 131 km/h (81 mph).[4]