Have you taken fluid mechanics? There are a lot more variables at work than just “a tapered look”. Note that Toyota uses a Kamm design on the Prius and most race cars are “Kamm-ish”. Lots of wind tunnel testing for those.
I have several patents on my work, but I did not work for Boeing. Just IBM and GE. Not a genius yet.
Andy
BSME,1979
Find a picture of a commercial jet that has blunt rear surfaces like a semitruck, instead of tapered tails. The kamm effect and toyota engineers...those japanese engineers will believe anything. There’s the story of how we let them steal a certain ship design from US in WWII, knowing they would copy it. Of course in the plan the center of gravity was above the center of buoyancy, what happened then when it slid out of dry dock? They’ll believe anything....
As to extensive wind tunnel testing, fish, birds, even airplanes flying in the real world have VAST experience in tapered vs blunt tails, you’re just trying to be cute or the devil’s advocate. Maybe you can hire on at airbus(airbust)and introduce them to the kamm effect and blunt tails.....
Sadly though, here the public whines about “freedom from foreign oil”. It should be “freedom from stupidity” as semitrucks roll on, pulled back into the suction zone of the hole they blow thru the air. A TAPERED TAIL would eliminate most of that rear aerodrag(fish tail)just as the aeroshell does over the cab(fish head).
Again, a box has 14 times the aerodynamic drag of an equal cross section torpedo, that’s right there in every physics book. In the movie : Flight of the Phoenix, the tail of the box is a tapered clam shell. Now if it works in a 300 mph aircraft, why not a 70 mph semitruck?
No, I’m not suggesting a solid shell tapered tail, it would either be a curved pyramid form made by an inflated balloon or open weave parachute, on a hinging frame, that deploys at high speed(above 35 mph), then retracts back onto the rear doors as the truck slows to a stop(below 15 mph). You could also have two (on each back door)that joined via magnetic zippers(top and bottom furrows to the rear point).
If this tapered tail boosts energy efficiency of the truck by 3 mpg, then on a 7 mpg rig : 7+3=10 mpg. With an annual fuel bill of $50,000, that’s about $15,000/year that stays in the trucker’s wallet instead of becoming the gov’t/big oil’s cash cow. So maybe you’re a front man for them with your kamm effect, or just intellectually lazy...