Why do superfast trains (maglev) have extra long noses even though the already look like airplanes (i.e. long tubes)?
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I haven’t heard this reason yet which is probably the main reason they are shaped that way.
I’m a former aerodynamicist so I know enough to make it look like I know what I’m talking about.
Most bullet trains are symmetrical front to rear so they don’t have to turn around when going back.
https://www.alamy.com/stock-photo-high-speed-train-vector-140744887.html
The optimal drag reduction shape in subsonic flow is a teardrop – where it’s round in the front and tapered in the back to a point.
Well if you have that shape, when you run it in reverse, it creates a huge amount of drag with the blunt rounded end now in the back.
If you have a pointy front, it’s not that much worse than a rounded front but the you also get the benefits of a nicely tapered back when running in reverse.
All Japanese high-speed trainsets have elongated noses, whereas Europeans trainsets don’t, even though they travel at the same speeds. The reason you would obviously think about is aerodynamics, but there are some significant engineering differences regarding tunnels between Japan and European countries.
In Japan the tunnels have one tunnel for both directions, the tunnels are quite narrow (small loading gauge) and the entrances are almost flat.
In France, there are actually two tunnels (one for each direction), the loading gauge is larger, the entrance angles are steeper.
In Germany, there is one tunnel for both directions, but the loading gauge is larger, and the entrance angles are very steep.
All these reasons make the tunnel boom much less a problem in Europe than in Japan, hence the much less elongated noses.
As others said, an airplane is on the air, no structures anywhere near them, on trains they’re extremely close to the ground, and that interferes with the train aerodynamics, if the trains were suspended further from the ground they would be shaped more like airplanes
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