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Ernie Rogers · 05-13-2009, 05:55 PM

Hello, guys,

About a week ago, I was asking for help on a little project, to predict the ideal high-efficiency car. Well, I have labeled that job "complete" and I'm on to a new one. (The document from the last project was posted today in the general efficiency forum.)

New project: To define the ultimate public transportation vehicle. Something better than a train, better than a bus, faster than a plane for short distances, say up to 200 miles. The premise of the new vehicle is that it will operate in a "transportation superhighway," a network with distributed control, with traffic routed for maximum throughput and efficiency.

The vehicle is presumed to travel on a rail and be small enough to provide near-point-to-point transportation. I am imagining a body of revolution sized to carry eight passengers--

7.8 ft diameter x 35 ft long (D/L = 0.21?)
200 mph design speed
Up in the air, no ground effect. Re = 20 million? (from memory)

My question: I guessed that a drag coefficient (based on frontal area) of Cd = 0.02 should be achievable. Could somebody help with this, verifying or improving this number? I was unable to find a place to get the information.

Ernie Rogers

05-13-2009, 05:55 PM	#1 (permalink)
Ernie Rogers Ernie Rogers Join Date: Feb 2008 Location: Pleasant Grove, Utah Posts: 133 Thanks: 0 Thanked 20 Times in 12 Posts	Help with transportation superhighway Hello, guys, About a week ago, I was asking for help on a little project, to predict the ideal high-efficiency car. Well, I have labeled that job "complete" and I'm on to a new one. (The document from the last project was posted today in the general efficiency forum.) New project: To define the ultimate public transportation vehicle. Something better than a train, better than a bus, faster than a plane for short distances, say up to 200 miles. The premise of the new vehicle is that it will operate in a "transportation superhighway," a network with distributed control, with traffic routed for maximum throughput and efficiency. The vehicle is presumed to travel on a rail and be small enough to provide near-point-to-point transportation. I am imagining a body of revolution sized to carry eight passengers-- 7.8 ft diameter x 35 ft long (D/L = 0.21?) 200 mph design speed Up in the air, no ground effect. Re = 20 million? (from memory) My question: I guessed that a drag coefficient (based on frontal area) of Cd = 0.02 should be achievable. Could somebody help with this, verifying or improving this number? I was unable to find a place to get the information. Ernie Rogers Last edited by Ernie Rogers; 05-13-2009 at 06:02 PM..