Holy piston! http://www.marketwatch.com/video/asset/the-1000-mph-car/643F47A7-B8DE-40C1-97E1-5F20D32D96A3#!643F47A7-B8DE-40C1-97E1-5F20D32D96A3 Thanks FChatter Darolls for this great link.
There was a 1:1 model of this at the British GP last year. Very impressive. They are touring UK schools to get kids interested which I think is great. http://www.bloodhoundssc.com/
Hey I have a question.... At these speeds... hell, at anything north of 250mph, aerodynamics definitely become the dominant force. At 1,000mph, that's even more so. So... 1000mph cars (or even 700mph 'cars') are really just aeroplanes with wheels instead of wings. In other words, what's the point? We have planes that have topped 2,100mph... power ain't the problem. The only problem is doing at this altitude (denser air), and having wheels on it. I guess I don't get the point of it.
I think the point is that it's just so difficult to do. It's like climbing Mt Everest. There's no point there either but it's a terrific accomplishment if you can do it. I think also the point about exciting kids in engineering is a good one. I was totally captivated as a kid in the Space Race. Today.... all you see is Steve Jobs holding up the lastest black or white widget in front of an audience. Kids have no understanding where it came from, how it was created, who did it, what you need to learn to do it, etc. He never talks about where this technology came from or the team of people needed to make it. It's just one big "Apple" logo and a man on a stage. So, I applaud this kind of thing. We need more worthless accomplishments that capture our imagination.
I take it your criticism is because the rocket engine doesn't propel the wheels as in a regular car? If that's your view, I can sortof understand it. It still is an enormous engineering challenge.
The fact is that it's a hell of a lot more difficult to move a vehicle at high speed if it has to stay on the ground than if it's in the air! An aircraft rans on only one medium: the air. All the physical contraints of high speed are the same all around the craft: friction, heat, turbulances, shock waves, etc... A high speed vehicle on land moves through one medium (the air), but a different support (the ground), and the effects of speed are completely different. At supersonic speed, a land speed record vehicle has to be kept on the ground, in spite of huge forces that push it to take off (with catastophic consequences of course) or flip over. So, it's not only the quest for speed that is the most difficult to satisfy, but the means to keep the vehicle on the ground, without hampering its speed, or making it unstable. It's a very difficult balance to obtain. Also, to reach supersonic speed, aircraft have no space limits. For a land vehicle, there is very few sites that can accommodate supersonic speed; usually deserts or dried lakes, of limited length. A supersonic car has to accelarate quicker than an aircraft to obtain its top speed much earlier, and then safely stop - and they restart the other way. That is quite tricky to realise; it needs intense concentration and nerves of steel, far more tham Mach 2 or 3 in a fighter jet! There is no room for error... When Andy Green broke the sound barrier at Black Rock in 1998, the ground was liquefying under the wheels of the car because of the effects of shockwaves. The car had to use parallel tracks for each runs. So, it's both a technical challenge and a human feat.
I think they wanted to incorporate the three various engines; Internal combustion, jet, and solid fuel. Hydrogen Peroxide would have been easier IMO. Aint no throttle or off switch on a solid fuel booster !
Jet is the main power, rocket is just for the top speed, IC engine is just to activate the rocket fuel pump.
There is on the Bloodhound SSC The solid rocket booster only runs while oxidant is pumped into it - if they want to stop it they shut off the pump (during the 20 second burn). The IC engine drives the rocket fuel pump which delivers 2100 lb of oxidiser to the rocket in 20 seconds http://www.bloodhoundssc.co.uk/ I love this challenge and have been following it from the start They originally had a bepoke V12 to power the pump but have clearly gone for a more reliable and tested engine.
I learned something new. Never heard of a hybrid solid fuel rocket engine before; [Hydroxyl-Terminated Polybutadiene (HTPB), a synthetic rubber, was selected as the primary fuel. Sectioned view of the 15.2cm hybrid rocket chamber All liquid oxidisers are hazardous, although the hazards take different forms. The most common is liquid oxygen, a cryogenic liquid with a boiling point of -183°C. It is difficult to handle and even minor contact with skin can result in serious frostbite. Nitric acid is another efficient, high-density oxidiser. It is however toxic, corrosive and gives off choking fumes. HTP, which we have selected as our oxidiser, is concentrated hydrogen peroxide H202 (in this case 86%, the remainder being water). It is a strong oxidising agent and has a high specific gravity (a desirable property in this application). It is non-toxic and although it can cause burns, rapid washing with water can reduce the effect to a mild bleaching of the skin. HTP was used in the UK space programme of the 1950s, 60s and 70s in rockets such as Black Knight and Black Arrow, which used liquid fuel engines burning kerosene. These programmes had an exceptional safety record. HTP is, however, very sensitive to contamination and can be easily decomposed by many common substances. It requires great care in handling and must only be allowed to come into contact with compatible materials; even then, storage tanks, pipe work and valves must be specially cleaned and prepared. HTP has one other advantage: it can be decomposed by a catalyst pack and therefore used as a monopropellant to provide thrust. At the top of the hybrid combustion chamber is the catalyst pack which contains 80 silver plated nickel mesh discs; these decompose the HTP into steam and oxygen. The reaction is given as: H202 → H2O + O2 + HEAT The decomposition generates a temperature of around 600°C enough to spontaneously ignite the solid fuel grain. This simplifies the engine by removing the need for a separate ignition system. BLOODHOUND SSC will carry 963kg (2100lbs) of HTP in a lightweight tank at 1.65bar (25lbs / in2). It will be supplied to the chamber by a high speed pump in this instance, one based on the design used on the Stentor rocket engine which powered the Blue Steel cruise missile of the 1960s. The pump was upgraded for us by its original designer and is now 15% more efficient. ] I did peg the Hydrogen Peroxide at least a bit. HTPB gives new meaning to the term "Burning rubber".
Hybrid engines have been around for a while by now. Spaceship 1 used it and Spaceship 2 will use it for its suborbital flights. You get the benefit of an easy to store/handle fuel while still being able to control it like a liquid fuel engine through the oxydizer. I flew one of these motors over ten years ago when High Power Rocketry was my hobby of choice.
