Slashdot Mirror
The Bloodhound Will Stay On the Ground At 1,000 mph
Hugh Pickens writes "BBC reports that engineers designing the world's fastest car, the Bloodhound SSC, built to smash the world land speed record of 763 mph set by the Thrust SuperSonic Car in 1997, believe they have a solution to keep the vehicle flat on the ground at 1,000 mph after initial iterations of the car's aerodynamic shape produced dangerous amounts of lift at the vehicle's rear. John Piper, Bloodhound's technical director, said: 'We've had lift as high as 12 tonnes, and when you consider the car is six-and-a-half tonnes at its heaviest — that amount of lift is enough to make the car fly.' The design effort has been aided by project sponsor Intel, who brought immense computing power to bear on the lift problem. Before Intel's intervention, the design team had worked through 11 different 'architectures' in 18 months. The latest modelling work run on Intel's network investigated 55 configurations in eight weeks. By playing with the position and shape of key elements of the car's rear end, the design team found the best way to manage the shockwave passing around and under the vehicle as it goes supersonic. 'At Mach 1.3, we've close to zero lift, which is where we wanted to be,' says Piper. In late 2011, the Bloodhound, powered by a rocket bolted to a Eurofighter-Typhoon jet engine, will mount an assault on the land speed record, driving across a dried up lakebed known as Hakskeen Pan, in the Northern Cape of South Africa."
Depends on if it's a fixed aero-surface vehicle or not. F1 cars had variable surface aero-parts for one or two years before they were outright banned. The idea was that you could increase the angle of attack to increase downpressure in the corners, but make the car aerodynamically neutral in the straightaways so you're spending more power on thrust rather than dividing it between thrust and downforce. Depending on how the rules for "world's fastest car" are written, how the aero is done determines how impressive this really is. If John Carmack can write a javascript to control thrust for a vertical takeoff rocket (Armadillo Aerospace), you can design a fast car with dynamic aerosurfaces. Building a fixed aero car that's neutral at 1000mph but won't fly into the air and flip when you hit a rock is a lot harder to do. Check out this hella sweet video of a Le Mans car doing exactly that at 220mph: http://www.youtube.com/watch?v=wM4guvo6Ifo
I'll admit this post was an excuse to post that video, but damn if it isn't cool. And that's at a quarter of the speed at which they'll be attempting this. It's not as easy as it looks.
Here's another cool video of the same thing happening. It's relatively common, even though they design against this exact sort of thing from happening. http://www.youtube.com/watch?v=y65oUlBMSUs
moox. for a new generation.
If this works it will be travelling across the land with a higher speed than anything that has ever travelled across the land, hence the title "land speed record". I agree with you that the wheel powered one is in some ways more important, but something has to be declared fastest land vehicle and it seems fitting for it to be the fastest vehicle on the land. If Fred Flinstone could run fast enough to make his car faster than any other car in history, would you deny him the land speed record?
Its a jet engine pushing it up towards 1000mph, but its a solid fuelled rocket (liquid oxidiser) that pushes it over.
A lot of their design towards the end of last year was deciding whether to put the Jet over Rocket (JoR) or Rocket over Jet (RoJ) in the tail of the vehicle.
They decided on the JoR configuration as it provided better stability & airflow through the jet.
This project is also about getting kids interested in engineering again, and they're making their data publicly available.
They've been touring with the full size model of the car visiting towns doing workshops with the school kids about the stuff they're doing and experiments & tests the kids can do themselves. They were kind enough to park the car outside my office when they were in my home town.