3 ms·
No, you don't save any energy by connecting them.
by goodpoint 5y ago
No, you don't save any energy by connecting them.
- sudosysgen 5y agoActually, yes, you do save energy by connecting them. You reduce wind friction by having them draft each other, and you reduce weight by having one large motor instead of multiple smaller ones.
- goodpoint 5y agoNo. We are talking about modern trains here. The wind friction is lowered in high-speed trains by making a flush body without interruption - and not by the connection itself. But this is besides the point. Each car has its engines and brakes, there is no significant push/pull force on the connections and there is no bigger engine somewhere. In the context of the current conversation the autonomous cars are electric and each car has its engines.
- throwawayboise 5y agoTFA shows a standard freight container on a rail car. Hardly aerodynamic, and cannot be coupled without gaps.
- LgWoodenBadger 5y agoI’m not sure you understand drafting and its uses/benefits in things like pelotons, bird migrations, and trains
- deepnotderp 5y agoBird migrations use v-formations to reduce induced drag not parasitic drag, eg https://www.nationalgeographic.com/science/article/birds-that-fly-in-a-v-formation-use-an-amazing-trick https://www.nationalgeographic.com/science/article/birds-tha...
- sudosysgen 5y agoI'm not talking about high speed trains. I'm talking about medium speed cargo trains. Despite the lack of a flush body, each container does draft the following one, greatly decreasing drag. Each car in a normal cargo train doesn't have its own engine. They are pulled by locomotives. This is more efficient than putting an engine in every car. Passenger trains typically do have engines in every car, but we're not talking about passenger train here.