1000-mph Car Planned

Smivs notes a BBC report on a British team planning a 1000-mph record-breaking car. The previous land-speed record broke the sound barrier. The proposed vehicle will get from 0 to 1,050 mph in 40 seconds. "RAF pilot Andy Green made history in 1997 when he drove the Thrust SSC jet-powered vehicle at 763 mph (1,228 km/h). Now he intends to get behind the wheel of a car that is capable of reaching 1,000 mph (1,610 km/h). Known as Bloodhound, the new car will be powered by a rocket bolted to a Typhoon-Eurofighter jet engine. The team-members have been working on the concept for the past 18 months and expect to be ready to make their new record attempt in 2011."

Comments

I've got a better idea

[elrous0]

How about a 1000 mpg car?

Re:I've got a better idea

[Ice Tiger]

How many land speed record attempts do you know that were done by vehicles intended for commercial production and sale?

Part of this project is to inspire the younger generation whilst at school that engineering and science isn't dull and boring and something worth getting fired up about. The UK has a shortage of home grown talent when it comes to engineering and this is helping change that for the future.

Re:I've got a better idea

[Wrath0fb0b]

Some simple calculations will show you that 1000 mpg (for g as in gallon of gasoline) is physically impossible.

(1) Energy content of gasoline --- 36.6 kWh/US gallon. Let's assume that your engine works at the absolute thermodynamic limit (40%) for a combustion engine so you get 16 KWH of work out of it.
(2) The power to move your vehicle through air is P = (1/2)(density)(projected area)(drag coeff)(velocity^3)
(4) At sea level, 25C, 60 MPH, A = (1 m)^2, CD = .1, you have to expend P = 1.25 KW to continue moving.
(5) In one hour, therefore, you have consumed 1.25 KWH ~ (1/12) gal. You have also moved 60 miles, giving you 60*12= 720 mpg.

So, even under the most generous conditions, you cannot possibly do better that 700 mpg. Of course, we have neglected rolling friction of the tires and assumed that your regenerative braking system is so good that you expend no net energy starting and stopping. 720 mpg is just the energy required to move the air out of your way as you cruise to work.

At first, I was going to mod you OT and move on, but I felt like there was something important to be said here -- efficiency is not like performance. In performance, one can always throw more energy at the problem (he's using a jet engine FFS, new sports cars are always breaking HP limits) but when going for efficiency, you are going to see diminishing returns. 100 mpg is doable, 200 mpg is doable with severe sacrifices (mainly in the comfort/cargo dept). Past that, I feel like the laws of physics are not going to be particularly kind.

Re:I've got a better idea

[Idbar]

"How many land speed record attempts do you know that were done by vehicles intended for commercial production and sale"

Precisely what I was saying pointless. How many NASCAR cars you can buy and drive on the streets?

I agree more on the F1 perspective, aerodynamics, handling, efficiency, safety, etc. Do you think land speed records provide mor "fun" than a circuit race?

I believe the old CART (now mixed with IRL) and F1 have more to take from.

Yes, you won't see an F1 in commercial production, but yet many of the technologies they have used are now available, such as semi-automatic sequential 7 gear transmissions, efficient gas engines, ultra light/safe materials. Now, what is it that this will provide to make the "engineering" world better and funnier except someone irresponsible driving at higher speeds?

Re:I've got a better idea

[Miseph]

Of course, one can always ignore your calculations by doing things differently than how you expect.

For example, what is the thermodynamic limit of fuel cells? What are the thermodynamic limits of every other alternative fuel or alternative engine type? What if we use more highly refined fuel that carries more energy per unit? What if you do not travel at 60 mph in order to lower wind resistance? Speaking of wind resistance, what if you were to travel through specially designed low air pressure conduits to make air resistance nearly 0? We can change all sorts of things about the situation to make your math, while good, completely irrelevant to the scenario.

When does it stop being a car?

[jonas_sten]

is it a car as long as it has wheels?

Re:Car? Or rocket on wheels?

[Anonymous Coward]

While I agree with your not-a-car sentiment, I think it is still a valid pursuit to attempt to break prior records. Generally, progress is measured by either surpassing previous measurements of progress, or by managing something entirely new. I think this qualifies for the former.

MPG is an obsolete measurement

[Shivetya]

I know it is not currently but it will be one day.

I like achievements like these. I know it costs a lot of money but my hat off to the engineers who can come up with these machines let alone the driver who dares to do it. Too many people want to sit on their couch and bitch secure in the safe little world and never get out to live life.

I know many will scream "whats the point". Well the point is that no one has done it, people claim it cannot be done, and throw in the challenge of trying. It gives kids something to dream about, perhaps sparking some enthusiasm for different careers.

Besides we might just learn something

Re:MPG is an obsolete measurement

[Anonymous Coward]

And how exactly does that make MPG "obsolete?"

Re:MPG is an obsolete measurement

[Ice Tiger]

Using a jet engine off the shelf isn't the hard part, btw the rocket is a HTP hyrbid rocket that is developed for this project.

The real brain cruncher is how you design a vehicle that can survive an environment where supersonic shock waves are being reflected off of a desert floor back onto the body of the craft and so on. Remember the wheels are travelling on the ground at mach 1.4, if they were uncovered the top of the wheel would be travelling at mach 2.8 with regards to the local airflow. That's up there with the SR71 in terms of velocity.

Hardly off the shelf.

Re:MPG is an obsolete measurement

[NoNeeeed]

As JFK once put it very succinctly...

"We choose to go to the moon, and do the other things, not because they are easy, but because they are hard"

If all we ever do is the easy stuff, nothing ever changes.

And for all the people saying this is easy, why don't you give it a try then? It isn't just the money, this stuff takes serious engineering and real talent on the part of the driver/pilot.

What amazing stuff have you done in your life?

Re:MPG is an obsolete measurement

[hey!]

Asking the point of engineering feats like this is like asking the point of sex being enjoyable. The point of sex being enjoyable is to encourage procreation. The point of engineering being enjoyable is to encourage creativity.

Of course, engineers like to see their creations at work, doing useful things, just like chefs love to see people eating. But speaking as an engineer who grew up in a restauranting family, you've got to be a little bit insane to go into either business. Nobody would become a chef unless they had a bizarre compulsion to cook. My brother went into that business, and you literally can't keep him away from the stove or the grill if there is cooking going on. The only reason he can sit still in a restaurant, I think, is professional interest in other aspects of the diner's experience, but even then he can't resist the temptation to host the meal, to buy drinks, to make suggestions for what to select from the menu. Some of his buddies have actually put full restaurant kitchens in their garages and spend their time off cooking.

When I visit my relatives, on the other hand, I find myself fixing their computer problems. I can't not fix their problems, even though I hate dealing with those kinds of messes. If cars were as easy to work on from general knowledge as they were forty years ago, I'd probably be fixing their cars too. I'm just addicted to the satisfaction of getting everything sorted out.

Re:MPG is an obsolete measurement

[kazamx]

I sometimes get the feeling the readership of Slashdot has aged over the last few years. The wonder excitement and enjoyment of doing something seems to be on the way out and cost/benefit productivity gains and other boring crap seem to be what people worry about. There was never a reason to go to the moon. There was never a reason to climb Everest. There was never a good reason to go to the North or South Poles. There was never good reason to do many of the cool things we did, that is until we did them.

Re:Stupid rules

[meringuoid]

I'd prefer to have car speed records for something that is remotely sensible, like 10 laps at Indianopolis, or 1 lap of the complete Nürburgring.

You can. But if you're interested in sheer speed, then it's straight-line records like this which are interesting.

So?

[Locke2005]

The proposed vehicle will get from 0 to 1,050 mph in 40 seconds.
Yeah, sure, but... how well does it corner?

Re:So?

[Just Some Guy]

lol something going that fast cant. at those speeds it litterly is flying. the gforces litterly pull it off the ground and its riding on them.

I feel dumber for having read that.

the point

[confused one]

Whatsthepoint

"Candy doesn't have to have a point. That's why it's candy" -- Charlie Bucket, Charlie and the Chocolate Factory

If you can't see the analogy... We may not be able to save you.

It's not 173 g, it's over 46000 g

[lars-o-matic]

Your typo: putting 2.8 (mach) in as 2.8 m/s.

Start over: centripetal a = v^2 / R

Plug in v = 476.5 m/s, R = 0.5 m (half of diameter); a = 454,000 m/s^2 approx.

Compare to g = 9.84 m/s^2 ; a is over 46,000 gee.