Design fixed for 1,000mph car - the 'Bloodhound'

[djellison]

I'm still not clear why this wouldn't be an acceptable attempt.

You have to have four wheels, two of which are steered, I believe - to be an FIA world land speed record. There are extensive rules and regs that dictate what is and what is not a land speed record car. A Eurofighter dragging an odometer isn't one. They had to split the rules to the unlimited category ( witness the jump from 400 - 600 mph in a few years in the 60's ) and the various wheel driven categories. There is also a grey area with vehicles like the Turbinator, and Bluebird CN7 which I think generated a little bit of thrust by virtue of the exhaust of the turbine power for their wheels. There are unlimited, jet, piston, turbine - lots of different categories out there.

Interestingly - almost the same team ( Andy driving, Ron designing ) hold the diesel land speed record - which is wheel driven, with JCB DieselMax. They're not a one trick pony, that's for sure.

Welding a wheel onto a Eurofighter would be easy. Making a car to travel Mach 1.4 - is not.

 

[pukifloyd]

1,000 mph...its just crazy...and cool

 

[0098386]

Yikes! Hammond would never survive a crash at that speed.

 

[pukifloyd]

btw i don't understand the need for making this car...i mean no one can use this so why spend millions just to break some record?!
I know its fun but i don't see any use for it!correct me if I am wrong!
(please do not bash me, its a genuine question! )

 

[edesignuk]

The Bloodhound uses a Eurofighter jet engine for propulsion after all.

Not quite...

According to wikipedia, it will use the jet engine to reach around 300mph, after that a custom built hybrid rocket engine will do the rest.

A prototype Eurojet EJ200 jet engine developed for the Eurofighter and bound for a museum, was donated to the project. This will take the car to 300 mph (480 km/h), after which a bespoke hybrid rocket designed by Daniel Jubb (nicknamed "Rocket Dan"), 24, from Manchester, who built his first rocket at the age of 5, and now supplies the US military, will boost the car up to 1,000 mph (1,600 km/h). A third engine, an 800 hp (600 kW) petrol engine, is used as an auxiliary power unit and to drive the oxidiser pump for the rocket. The jet engine will provide nine tonnes of thrust and the rocket will add another 12.

The four 36-inch (910 mm) diameter wheels will rotate at up to 10,500 rpm and will be machined from solid titanium to resist the 50,000 g centrifugal forces.

 

[robbieduncan]

btw i don't understand the need for making this car...i mean no one can use this so why spend millions just to break some record?!
I know its fun but i don't see any use for it!correct me if I am wrong!
(please do not bash me, its a genuine question! )

Part of the purpose of this team/attempt is to inspire the current and future generation of British school kids back into science and engineering...

 

[djellison]

i don't see any use for it!

From www.bloodhoundssc.com

So from this background we derived BLOODHOUND SSC’s very clear objectives:

1. To create a national surge in the popularity of Science Technology, Engineering and Mathematics (STEM) subjects

2. To create an iconic project requiring extreme research and technology whilst simultaneously providing the means to enable the student population to join in the adventure

3. To achieve the first 1000 mph record on land

4. To generate very substantial and enduring media exposure for sponsors

Very Noble (pun intended) and worthwhile reasons, all.

Your question reminds me of a section in Noble's autobiography (Thrust) where it might be Thrust 2 or Thrust SSC - he wrote to the Department of Trade and Industry suggesting they might like to leverage the power of the project as a promotional item for UK PLC, globally. Some months later they wrote back, and I miss-quote slightly, but their response was basically:

"The project sounds fascinating. When do you expect to put the vehicle into production, and how many will you produce per year?"

They just didn't get it.

 

[RedTomato]

You have to have four wheels, two of which are steered, I believe - to be an FIA world land speed record. There are extensive rules and regs that dictate what is and what is not a land speed record car. A Eurofighter dragging an odometer isn't one.

Welding a wheel onto a Eurofighter would be easy. Making a car to travel Mach 1.4 - is not.

Thanks for that info. Looking at the BBC article the OP linked to:

The dried-out lake bed had the perfect surface for the record attempt, said Bloodhound's driver, Wing Commander Andy Green.

"It's hard enough to support a six-tonne car on metal wheels but soft enough to allow the wheels just to sink in maybe 10mm," he told BBC News.

"That gives the damping, or compliance, we need; but it also gives me the lateral grip that allows me to steer the car at slow-to-medium speeds. At high speeds, it's not so important because the bits of the wheel that stick out of the bottom of the car act as an effective rudder."

So from that, I gather that the car is steered via wheel/ground interface at low speeds, but at high speeds, i.e. when doing the high-speed 'flying KM' record attempt, the two steering wheels basically become rudders. Steering is then from how the angle of the wheels affect the air flowing past the car.

So basically a low flying aeroplane. I think we can agree on that.

Now to stretch a point for the sake of argument : take the Eurofighter aeroplane, I think it just happens to have only 3 wheels on the undercarriage, so we put an extra one on, next to the small one at the front. 4 wheels. We put a small electric steering motor on the front wheels. 2 steering wheels.

Now do whatever needed - take a long run-up, then fly at a computer-set laser-guided 1.5 metre height with the undercarriage only just touching the ground, taking a tiny bit of weight, and use the angle of the front wheels as a rudder. Would that meet the regs?

 

[edesignuk]

So from that, I gather that the car is steered via wheel/ground interface at low speeds, but at high speeds, i.e. when doing the high-speed 'flying KM' record attempt, the two steering wheels basically become rudders. Steering is then from how the angle of the wheels affect the air flowing past the car.

That's not how I read it. They're saying that at high speeds the surfaces of the wheels act like rudders, in that the air passing by them dictates direction to some degree, but the wheels are still on the ground, and the wheels are still doing the steering, all controlled by the steering wheel.

 

[robbieduncan]

All this talk of Eurofighters dragging undercarriage/wheels at 1000mph is pretty silly in my view: the Eurofighter is simply not designed to do that and would, most likely, crash attempting such a manoeuvre. Remember that it doesn't have to just touch it's wheels down for a short time: it would have to remain in contact with the ground for a whole mile. The slightest turbulence and it would either loose contact with the ground or crash into it.

Edit to add: I'm pretty sure the vehicle has to be 100% piloted/driven by the person on board. Computer controlled/laser guided stuff will not qualify. Are you brave/stupid enough to try flying an aircraft at Mach 1.4 that close to the ground for that far?

 

[djellison]

Would that meet the regs?

No - it's patently not a car - it's an aircraft designed to leave the ground. Furthermore, at 1050 mph, your Eurofighter would shed its undercarriage VERY quickly. I doubt even if the undercarriage were invincible, that the power of the Eurofighter would take it through to Mach 1.4 with the undercarriage deployed. Bloodhound is a far sleeker shape than a Eurofighter, and yet it has more thrust than a Eurofighter. Try and get the undercarriage of ANY aircraft to do mach 1.4 and they would instantaneously explode.

Bloodhound is a car. It has to stay on the ground and that's damn hard. It has to have wheels that pull tens of thousands of G on their rim. That's damn hard. It's got to withstand the interactions of shockwave, ground, and bodywork. That's damn hard. All things no aircraft has to do. It may involve a HUGE ammount of aerospace technology, but a car it is.

The definition via the FIA

CATEGORY C (Special vehicles in accordance with the definition given under Art. 13)

These vehicles may be sub-divided according to the type of engine used (jet, rocket, etc.).

Article 13 of the International Sporting Code :

Land Vehicle, Automobile, Special Vehicle, Ground Effect Vehicle

Land Vehicle :
Vehicle propelled by its own means in constant contact with the ground either directly by mechanical means
or indirectly by ground effect, and the motive power and steering system of which are constantly and entirely
controlled by a driver on board the vehicle.

Automobile :
A land vehicle propelled by its own means, running on at least four wheels not aligned, which must always be
in contact with the ground; the steering must be ensured by at least two of the wheels, and the propulsion
by at least two of the wheels.

Special Vehicles :
Vehicles on at least four wheels which are propelled otherwise than through their wheels.
.

You do some somewhat determined to degrade the project or make it seem trivial. Why?

 

[RedTomato]

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[RedTomato]

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[RedTomato]

the Eurofighter is simply not designed to do that and would, most likely, crash attempting such a manoeuvre. Remember that it doesn't have to just touch it's wheels down for a short time: it would have to remain in contact with the ground for a whole mile. The slightest turbulence and it would either loose contact with the ground or crash into it.

1200mph is just over 500 meters per second. The flying KM (not a mile) that the record is measured over would take under two seconds.

Flying just above the ground is one of the most stable flight modes for aircraft - the ground-effect forms a cushion of air that the aeroplane can cruise on. At 1200mph, you need pretty flat ground, which is exactly what we have here.

Edit to add: I'm pretty sure the vehicle has to be 100% piloted/driven by the person on board.

That does make a big difference, and would clearly exclude most modern aircraft. Are you 100% sure Bloodhound and Thrust SSC have a strictly mechanical linkage between the steering wheels and the driver?

Thrust SSC had two jet engines, one on either side. Undoubtedly it had electronic / computer assisted thrust balancing, and I'd call that quite a big help in steering the car. Remember, 'steering' here means just going in a straight line. No turns or corners needed.

You do some somewhat determined to degrade the project or make it seem trivial. Why?

I admire Bloodhound, and I loved Thrust SSC, I just don't see it as a car, more of a low-flying rocket with wheels or an aeroplane with fixed undercarriage. That doesn't make the people who design, build and fly them any less than 100% heroes.

Bloodhound and Thrust SSC are far more dangerous than aeroplanes - when I travel at 400+mph, I'm always a safe mile+ away from the ground and any other hard objects. Not dangling an inch from the hard ground like these insane folks.

But to me, a LAND SPEED record means propulsion via pushing against the ground, full stop. That means a high speed train, running on rails at 1000+ mph would be fine for a land speed record, as long as the propulsion power was through the wheels. But the FIA would probably disallow it because they're car nuts. I seem to recall they specifically say rails are not allowed. I'm more open minded than the FIA here

The meaning of propulsion from reaction against the ground might also include an electro-magnetic rail-gun style land speed attempt.

Propulsion is from the EM field, with the vehicle pushing against the field exerted by the rails, which form part of the ground. To be fair, you could say that all the energy for the EM fields must be generated on board the vehicle, and not supplied by external generators, which would make a rail-gun (or coil-gun) scenario a much, much harder idea.

 

[TuffLuffJimmy]

You do some somewhat determined to degrade the project or make it seem trivial. Why?

I don't think that's RedTomato's point. No where did he say this feat any less impressive than it is. He simply stated he doesn't feel it's a true groundspeed record.

That's fine. I don't consider a panda a true bear (despite what science tells me now) that doesn't make it any less interesting.

 

[djellison]

Are you 100% sure Bloodhound and Thrust SSC have a strictly mechanical linkage between the steering wheels and the driver?

Yes - there are interesting articles on the exact steering ration they wish to use on . It MAY have been power assistedb ut the inputs were fully Andys.

http://www.bloodhoundssc.com/car/steering.cfm

How about automated steering, or some kind of ‘fly-by-wire’ computer stabilisation? No – the rules do not allow it, and quite right too in my opinion. In order to be a land vehicle in LSR terms, the FIA rules require that the vehicle is ‘wholly and continuously controlled by the driver’.

Thrust SSC had two jet engines, one on either side. Undoubtedly it had electronic / computer assisted thrust balancing

It's didn't. It had two linked throttles - and a gauge in the cockpit that told Andy of the thrust difference between them. Indeed, one engine tended to lead another when going onto full afterburner - he even commented during the final run that the other engine lead which made a nice change.

I just don't see it as a car,

Well - those who define such things say you're wrong - and I agree with them. No airplane has wheels that survive 1050 mph. No airplane HAS to stay on the ground.

But to me, a LAND SPEED record means propulsion via pushing against the ground, full stop. .

That's the wheel driven category, in which there are sub catagories for piston engines, and turbine engined. The outright record mentioned earlier for wheel driven - the late Don Vesco's turbinator - used the turbine from a Chinook - the exhaust for which would have created a non negligable ammount of thrust. Does that make it's record any less impressive? And if not, then at what point of wheel driven and thrust driven do you question it?

If you want a record with rails - then the rocket sled ranges in the US can regularly go into several mach numbers. Just got to find a human who can survive the multiple tens of G's at each end of the ride. Truthfully - that's not much of an engineering challenge.

But it's not a World Land Speed record. The constraints set for the World Land Speed record make it a huge engineering challenge. If it were easy - everybody would be doing it.

 

[RedTomato]

It's didn't. It had two linked throttles - and a gauge in the cockpit that told Andy of the thrust difference between them. Indeed, one engine tended to lead another when going onto full afterburner - he even commented during the final run that the other engine lead which made a nice change.

That's really cool - thanks for the info. That's definitely me answered there.

That's the wheel driven category, in which there are sub catagories for piston engines, and turbine engined.

I prefer to focus on speed created by pushing against the ground, which can be done in different ways, not just by wheels.

If you want a record with rails - then the rocket sled ranges in the US can regularly go into several mach numbers. Just got to find a human who can survive the multiple tens of G's at each end of the ride. Truthfully - that's not much of an engineering challenge.

I specifically said any rail attempt must be propelled by pushing aginst the ground, which is why I started talking about EM rail-guns. Current designs also generate 100's of G's. But they 'cheat' by using power generated outside the vehicle. Which is why I said the EM power should be generated on board. That's definitely a very interesting engineering challenge.

Would a Bloodhound propelled by external laser driven ablation be acceptable? Or a Bloodhound with electric motors that took their power from a cable strung along the playa? (world's fastest tram )

But it's not a World Land Speed record. The constraints set for the World Land Speed record make it a huge engineering challenge. If it were easy - everybody would be doing it.

I understand the emotional reasons for not allowing rocket sleds on rails, even if it doesn't make much logical sense. What I don't understand is why ban rails full stop, even wheel-driven rail systems?

The simpliest answer is the FIA are a bunch of car nuts, yes?

 

[djellison]

The simpliest answer is the FIA are a bunch of car nuts, yes?

You've got 3 guesses what the A in FIA stands for

The first two don't count.

Laser powered? That wouldn't be self propelled. Running like a tram? Wouldn't be self propelled. They have to self powered. Run it on rails? It's not a LAND speed record - it's a RAIL speed record.

No one has 'banned' rails. There is an entry for the guinness book of records for rocket sled mounted vehicles, I am sure.

But if you want to get the FIA World Land Speed Record...you've got to follow their rules, and those rules make it a very tough engineering challenge. That challenge is what makes it such an exciting proposition and so powerful as a tool for education.

 

[RedTomato]

It's not a LAND speed record - it's a RAIL speed record.

Agree with your other points, but the point I have been making ever since the start of this thread (feels like it!) is that rails are also a part of land. So rails should be eligible to be a part of a land speed record.

(As well as being self-propelled and pushing against the land, not the air.)

 

[robbieduncan]

It would appear that a team are trying to, more or less, take a jet fighter, remove the wings and fit wheels to go for the record. The North American Eagle.

I would note that unless they succeed soon they may well not bother: their projected top speed is lower than Bloodhound...

 

[RedTomato]

It would appear that a team are trying to, more or less, take a jet fighter, remove the wings and fit wheels to go for the record. The North American Eagle.

I am vindicated

Removing the wings will remove a lot of drag and weight (these wings are designed to take high-G and inverted G loading forces), and I suppose they don't need much fuel storage for the record attempt.

 

[robbieduncan]

I am vindicated

Perhaps if/when they have a successful run/get the record.

 

[djellison]

I am vindicated

Really?

Then why don't they have the record already?

Why's it taken them so long- land speed records are just low flying aircraft, right - just cut the wings off and go for it, right?

 

[RedTomato]

Perhaps if/when they have a successful run/get the record.

Really?
Then why don't they have the record already?

Why's it taken them so long- land speed records are just low flying aircraft, right - just cut the wings off and go for it, right?

It doesn't matter whether they get it or not - though I wish them good luck in the attempt, same as for the Bloodhound crew. The point is that this modified aeroplane is apparently accepted by the FIA as a valid record vehicle, and also that the team involved though that it was worth spending millions of dollars on this design.