jet powerd car

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El-Kablooey
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Re: re: jet powerd car

Post by El-Kablooey » Fri Aug 19, 2005 2:39 am

pezman wrote:N2O hybrid rockets seem to be in vogue and are reportedly very simple to build.

http://www.popularmechanics.com/automot ... page=3&c=y

I'm sure that would work well, but again you are dealing with fairly high pressure gas. That kind of increases the danger factor a bit. You would have to carry alot of N2O also, It would take alot less volume of H2O2 because it is already in its most dense state, and the higher oxygen content, also the hydrogen supplements the fuel. If I was going to build a liquid-fueled rocket engine I believe that I would use the fuel/H2O2, I think it is the best solution for an amatuer.



Hoy crap, I just went to that polular mechanics link. That's pretty darn impressive alright! Can you imagine going 0-60mph in 5 seconds on a mountain bike? hahaha, I may have to do this!!!!!!!!!!!!!!!! I haven't broken any bones in a few years, and I'm sure the nurses miss me. :)
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re: jet powerd car

Post by Mr. Yuk » Fri Aug 19, 2005 5:35 am

Be careful however, buying high concentrations of H2O2 can earn you a place on "the list". High concentration H2O2 +15% are the main precursor in explosive peroxides like tri-acetone tri-peroxide, methyl-ethyl ketone peroxides, hexamethelenediammine peroxide, and so on. But if you are interested the cheapest I have ever bought was from a hydroponics supplier http://www.hydroempire.com/ they carry 35% H2O2 by the name of Oxyplus for $30 a gallon, but here was the kicker-free shipping! No hazmat! I don't want to disappoint you but they may no longer have the free shipping.

I have found that a good method for concentrating the hydrogen peroxide in a solution dihydrogen monoxide :) is boiling the mixture at about 100*C. H2O2 boils at about I believe 150*C, so you can boil off the water but it may be difficult to accurately determine the concentration of the peroxide.

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Re: re: jet powerd car

Post by El-Kablooey » Fri Aug 19, 2005 4:19 pm

Ben wrote:The hydrogen in H2O2 doesn't "supplement the fuel". Hydrogen peroxide breaks down into water and oxygen.

Liquid fueled rockets require fuel pumps capable of pumping at whatever pressure you want the chamber to be at, which can be difficult. And high purity (>90%) peroxide is difficult to get.

The danger of having pressurized nitrous oxide is the advantage of not needing an oxidiser pump, and the advantage of a solid fuel grain is not needing a fuel pump.

All you need is 50% H2O2, and it can be easily refined to 62% by freezing. You only need >90% if you want to make a peroxide rocket that only uses peroxide and a silver catalyst.

And Mr. Yuk, who cares if you are on any list, if you are using the peroxide for legal purposes. I don't think it is watched anyhow, you cango in any swimming pool supply store and buy it, cash.
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re: jet powerd car

Post by Mr. Yuk » Fri Aug 19, 2005 4:43 pm

I suppose you're right, especially if you live in the US.

Ben wrote: "The hydrogen in H2O2 doesn't "supplement the fuel". Hydrogen peroxide breaks down into water and oxygen"

H2O2 decomposes into H2 and O2 correct? Only after it has combusted does it become H2O and oxygen.

H2O2 ==> H2 + O2 ===> 2(H2) + 2(O2) ==> 2(H2O) + O2

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re: jet powerd car

Post by El-Kablooey » Fri Aug 19, 2005 8:04 pm

I think he was confusing using h2o2 for an oxidiser and usnig h2o2 And silver catylist, like in "rocketman's" jetpack, it breaks down into steam and oxygen.
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re: jet powered car

Post by Oxydro » Mon Dec 05, 2005 7:07 am

I have been wondering about an idea, don't have any clue whether or not it would work: Take a giant supercharger-type thing (belt-driven compressor turbine), and use it to feed air to a combustion chamber equipped with a nozzle. It seems that although it would eat some torque from the engine, it would provide more thrust than it wasted.

Just to clarify, I mean this to be a performance booster on a car: instead of a whole turbojet, just have the front of a turbojet but belt-driven, and then a ramjet or rocket-style rear end. Cheaper than a turbojet I would guess if you already have the engine powering it, and I would think that would give a higher power density. Just a rocket fed with compressed air generated on the spot, is another way to look at it.

You might want to have some kind of clutch system to control when the compressor runs, maybe it isn't really needed. Anyway, feel free to tell me it's a dumb idea, but I don't know the physics well enough to be able to see that for myself.

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re: jet powerd car

Post by patrick35 » Mon Dec 05, 2005 11:31 am

hi oxydro .

if you take a large super chage like those on top-fuel dragster , how are you gonna drive it ??? how many horse power did you think you need to drive the super charge ???

me i know , on a top fuel dragster the engine devlope approx... 6000 HP at the crank shaft .
if you can provide the amont of compressed air those engine need with out driving the charger by the belt , you will heve 10 000 to 12 000 HP ....
yep ,,,,,, to produce 60 PSI at the air flow those engine need it take around 5000 HP to drive it ........

so now with what kind of engine you will drive your super charge to feed your pressur jet ,?????????????????

patrick .

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re: jet powerd car

Post by Anders Troberg » Tue Dec 06, 2005 7:19 am

If that's true, it sounds like it would be a good idea to drop the supercharger and instead bring a tank of compressed air (or why not NOS while you're at it...) with you in the dragster. That much extra horse power would certainly justify some extra weight.

I doubt it, though, for the simple reason that there is no way I can see that simple belt transferring 5000 hp without being torn to shreds.

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re: jet powerd car

Post by patrick35 » Tue Dec 06, 2005 11:08 am

hi ANDERS .

did you know , after each 1/4 mil , those top fuel dragster , the engine is completely renewed , the super charge belt is change for a new one , the super charge is good for only fore run , yep every 1 mil the super charge have to be rebuild .
the belt that drive the super charge are not those you can find in a car shop , they are specialy made for those hight power engine and they cost 2500 $ us . you can find a similar belt in a speed shop for 200 $ .

whene i told the engine is rebuid , i mean , it's everything is change .
even all the bolt except those for the valve cover are change , and you don't find those bolt at wal-mart ......
the crankshaft is good for 2 run , yep the crankshaft twist , because those engine ave more then estimated 7000 foot-pound of tork .
yep estimated because no one of thise engine can run on a dyno machine , the engine will be destroy before endding the run .

patrick .

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re: jet powerd car

Post by Anders Troberg » Tue Dec 06, 2005 12:45 pm

Yep, I know how much attention the engine gets and how long the estimated lifespan is.

Still, 5000 hp on a belt, regardless of how special it is, seems a lot. If the belt can take that, it would be more or less strong enough to take the power from the engine to the wheels. In my head, that just seems wrong.

I have no doubt the supercharger takes a lot of power to run, but 5000 hp is a whole lot of power. We're talking about something like half the power of a locomotive, 12 large trucks or 5000 mopeds, all transferred through a belt.

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Re: re: jet powerd car

Post by Viv » Tue Dec 06, 2005 3:13 pm

Anders Troberg wrote:Yep, I know how much attention the engine gets and how long the estimated lifespan is.

Still, 5000 hp on a belt, regardless of how special it is, seems a lot. If the belt can take that, it would be more or less strong enough to take the power from the engine to the wheels. In my head, that just seems wrong.

I have no doubt the supercharger takes a lot of power to run, but 5000 hp is a whole lot of power. We're talking about something like half the power of a locomotive, 12 large trucks or 5000 mopeds, all transferred through a belt.
I seem to remember a cenrifugal compressor takes around 100 hp to move one pound of air per second, a pound of air a second is a lot:-) even a small aircraft turbine uses 2500hp to drive the compressor stage, up to 20,000Hp is not unheard of, correct me if I am wrong this is from memory.

The Mercedes K engines (Kompressor) V8 E55 takes over a 100Hp to drive the supercharger and thats a small road going version, 500HP output from the engine but 600Hp really.

Viv

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re: jet powerd car

Post by Al Belli » Tue Dec 06, 2005 4:21 pm

Hi,

According to Treager, Hp. required for a compressor = 0.338 X F X Lb.

where F = degrees Fahrenheit of temperatore rise in the compressor

Lb. = pounds of airflow through the system

For example:

A turbojet with 600 F. rise and 200 Lb. flow, will require 40,000 + Hp.


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re: jet powerd car

Post by Al Belli » Tue Dec 06, 2005 5:02 pm

Hi,

A drag engine flowing 1,300 CFM with a boost pressure of 15 PSI will require slightly over 5,000 Hp. to drive the supercharger. ( at 100% efficiency )

Al Belli

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re: jet powerd car

Post by Viv » Tue Dec 06, 2005 6:15 pm

Nice figures Al thanks for that,

its all ways worth keeping in mind when we compare turbines and other engines to pulse jets that they pay a lot for their compression and air flow, we on the other hand only get a little in comparison but it all comes from just the sound of an explosion:-)

Viv

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