Weird looking train

[Mich the Tester]

http://www.seat61.com/images/Norway-oresund-train.jpg

I’m just arranging my trip to the Stockholm Tens
and while booking the train tickets I came across this picture of the Copenhagen to Stockholm train. What a strange looking contraption. Aside from the aesthetic eccentricities, I wonder how good the aerodynamics are at 160km/h.

[cailin maith]

http://www.seat61.com/images/Norway-oresund-train.jpg

I’m just arranging my trip to the Stockholm Tens
and while booking the train tickets I came across this picture of the Copenhagen to Stockholm train. What a strange looking contraption. Aside from the aesthetic eccentricities, I wonder how good the aerodynamics are at 160km/h.

Oh my goodness... that seat61 is brilliant isn't it? Only found out about it when I was in trailfinders on Saturday - I've been a bit addicted to it since

[DaveB]

http://www.seat61.com/images/Norway-oresund-train.jpg

I’m just arranging my trip to the Stockholm Tens
and while booking the train tickets I came across this picture of the Copenhagen to Stockholm train. What a strange looking contraption. Aside from the aesthetic eccentricities, I wonder how good the aerodynamics are at 160km/h.

Probably rather good. The area in front of the cab will catch a cusion of air and hold it there. Oncoming air as the train moves forward will be pushed around this cusion with far less friction than any 'streamlined' surface.

[suityou01]

Probably rather good. The area in front of the cab will catch a cusion of air and hold it there. Oncoming air as the train moves forward will be pushed around this cusion with far less friction than any 'streamlined' surface.

Cobblers. That train is as aerodynamic as Dame Edna Everidge.

[Churchill]

Cobblers. That train is as aerodynamic as Dame Edna Everidge.

Wow, impressive, FEA and Laminar Airflow simulation all done by sight!

[Mich the Tester]

Probably rather good. The area in front of the cab will catch a cusion of air and hold it there. Oncoming air as the train moves forward will be pushed around this cusion with far less friction than any 'streamlined' surface.

Cool theory. So why aren't more fast moving things shaped like that?

[doodab]

Cool theory. So why aren't more fast moving things shaped like that?

A train is exceptionally long and thin, so the drag due to the overall surface area is the dominant factor in determining the drag coefficient. Having a blunt end isn't *that* big a deal.

[Mich the Tester]

A train is exceptionally long and thin, so the drag due to the overall surface area is the dominant factor in determining the drag coefficient. Having a blunt end isn't *that* big a deal.

No, but I'm trying to find ouot more about DaveB's theory that the cushion of air would be so effective.

[doodab]

No, but I'm trying to find ouot more about DaveB's theory that the cushion of air would be so effective.

It would make very little difference. The difference between a a blunt end, pointed end or (highly dubious) magical cushion of air is going to be tiny compared to the drag due to the overall surface area and turbulence underneath the train.

If aerodynamics have anything at all to do with the shape it's most likely because that shape means that when they join multiple trains the gap between carriages is less prominent which makes the overall train more aerodynamic.

[Mich the Tester]

It would make very little difference. The difference between a a blunt end, pointed end or magical cushion of air is going to be tiny compared to the drag due to the overall surface area and turbulence underneath the train.

If aerodynamics have anything at all to do with the shape it's most likely because that shape means that when they join multiple trains the gap between carriages is less prominent which makes the overall train more aerodynamic.

So why do very fast trains like TGVs, pendolinos, ICE and so on have an aerodynamic front end? Is it to keep the front on the ground? Does the effect of wind resistance increase exponentially with speed? Or is it just to look cool?