How the North American Eagle works
By Marshall Brain
http://www.JewishWorldReview.com | (MCT) On October 15, 1997, Andy Green set the Land Speed Record of 763 MPH. It was an amazing feat - the first time ever that a car had officially broken the sound barrier. Since then, no one has come close.
In 2007 there are at least two teams that are going to try to break the record. One is led by Steve Fossett, who in January of 2007 purchased the Spirit of America car from Craig Breedlove. The other team is led by Ed Shadle and Keith Zanghi. They have built a jet-powered car named the North American Eagle.
The thing that makes the North American Eagle interesting is the fact that it started life as a Mach 2 jet fighter. The team purchased a decommissioned F-104 Starfighter and used it as a starting point. By removing the wings, covering over the mounting points for the wings and then adding wheels and a parachute braking system, the team created what could become the fastest car in the world.
The North American Eagle uses a GE LM-1500 jet engine as its power plant. The LM-1500 is an extremely powerful engine that can generate up to 52,000 horsepower and 20,000 pounds of thrust. The operation of this engine is nothing like the operation of a normal piston engine like the one in your car. Along the side of the North American Eagle are the F-104's original air intakes. The engine compresses air from these intakes in its 17-stage compressor section, adds fuel, lights the fuel and then sends the thrust straight out the back of the engine. At full throttle, the engine burns over a gallon of fuel every second, and the afterburners add another 10 gallons per minute of gas to that.
To turn the F-104 into a car, a team of engineers first stiffened the frame of the jet. Then they added three wheels. The single front wheel provides steering, and the two back wheels are mounted on a 10-foot wide metal triangular frame to provide stability. To date, the North American Eagle has been running on rubber tires. But for the speed record, where the goal is 800 MPH, rubber tires would disintegrate. So the team will use large, solid aluminum wheels. Each wheel is machined out of a massive billet of aluminum for strength.
The engine weighs almost two tons. Add to that the F-104's fuselage, the wheels and the wheel's frame and you have a vehicle that weighs in at approximately 13,000 pounds. There is also likely to be approximately a ton of fuel onboard.
So, how do you bring 13,000 pounds of car traveling at 800 MPH to a stop? It is a five-step process that goes something like this. The first step is to use the speed brakes built into the original airframe. Two large doors near the tail open using hydraulic cylinders. They are able to cut the speed from 800 to 650 MPH. Then a small drogue chute pops out to bring the speed down to about 500 MPH. Then the two main parachutes deploy and bring the car down to about 125 MPH. Since the wheels are solid aluminum, there is also a magnetic braking system that generates eddy currents in the wheels to create drag.
And then there is the last 100 MPH of velocity that needs to go away. Some cars have used normal disc brakes to come to a complete stop. But at 13,000 pounds, disc brakes have their limits. The North American Eagle will probably use a hydraulically activated pad that pushes into the ground. The best part of this approach is the fact that it is fool-proof.
Right now the North American Eagle team is at an interesting crossroads. The car is done, and the car has been tested on rubber tires to speeds up to 300 MPH or so. But now the team needs to find a major sponsor to make an attempt at the Land Speed Record. Steve Fossett has indicated that his team may make an attempt in October of 2007. With luck, the North American Eagle team will be able to get there first.
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© 2007, How Stuff Works Inc. Distributed by McClatchy-Tribune Information Services.