I had a friend that had a train that had a flexible tube with slots aimed forward. When the train passed over it, the air would push it along. It was from the 1960's World Fair. So, in fact yes, you can blow around a turn. Roller coasters work by getting the car to the highest point then letting them "Roll" the rest of the way. They are not powered unless going up another very steep rise.
Did someone just want a model of one or a working one?