Need a book? Engineering books recommendations...
High-speed vs conventional train[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: "Sseaint Org" <seaint(--nospam--at)seaint.org>
- Subject: High-speed vs conventional train
- From: "gregory szuladzinski" <ggg(--nospam--at)bigpond.net.au>
- Date: Sat, 30 Oct 2010 19:21:36 +1100
When you ride a HST, the feeling is similar to that being on a plane,
but with different ups and downs.
Now, to nit-pick (right spelling?) on the opinion below.
Work is force multiplied by a distance travelled.
The multiplier of 27 is on the force. The distance covered, in a unit of time, is 3x larger,
so the energy needed is 9x larger.
But the aero resistance is only a part of the total, so energy input will not grow that much.
Also, the aero shaping is better, which further descreases the multiplier.
The frequency-of-use factor will divide the result by 3.
Gregory from Oz
On Fri, Oct 29, 2010 at 11:53 AM, IRV FRUCHTMAN <ifaeng(--nospam--at)yahoo.com> wrote:
> Fellow Engineers,
> High speed trains are wonderful engineering feats, but I don't believe
> saving energy is one of them. As I recall from my school days: drag force=
> proportional to speed squared and power (read energy) is proportional to
> speed cubed. Therefore a train moving at 300 mph, compared to a train at =
> mph, uses (300/100)^3 =3D 27 times as much energy. If the requirement f=
> the number of trains is reduced by 1/3 =96 to move the same number of peo=
> then the increased energy use is 27/3 =3D 9. Therefore, 9 times as much e=
> is required to move the same people/ load with a high speed train as
> compared to "low" speed train.
> Given a choice, I'll take an airplane.
- Prev by Subject: RE: high tech parking garage
- Next by Subject: Hip Roofs and Parallel to Ridge
- Previous by thread: RE: China's high speed rail
- Next by thread: More Useful Steel Tables