Peter Parry wrote:
On 30 Apr 2011 21:29:53 GMT, Steve Firth wrote:

The Natural Philosopher wrote:

Average clipper ship speed was a little over a fast walking pace.
A clipper ship could make 17 - 18 knots.

It COULD. But if you bother to learn English, you might see that I said
'average'

ON average, they did not. Due to having to cover huge extra distances in
tacking, or simple lack of wind.

150-250 miles a day was a good speed for any fast sailer.

6-10mph. And highly dependent on the wind.




No steamship was as fast as a clipper.

A more valid comparison would be with a modern cargo ship. The Emma
Maersk has a cruising speed, typical for a large cargo ship, of 25
knots (although recently 20kts and in some cases speeds as low as 12
kts have been used to lower costs). Whilst the tea cutters averaged
(unpredictably) about 17kts

No, they AVERAGED about 8-9 knots at best.

the more usual sailing cargo vessel
managed about 8kts.

No, they AVERAGED about 5 knots.


Apart from predictability the killer for sail ships was of course the
cost per ton of cargo and also the Suez Canal - which sailing ships
could not use reliably. The Suez Canal made steam ships, of no
greater average speed than the best clippers, far faster and much more
reliable on the India and Far East routes while the clippers still
went out by the Trade Winds and home by the Cape of Good Hope. In 1875
the Cutty Sark came to the UK from Shanghai in 108 days, but the SS
Glenartney took only 42 days through the canal.

The Cutty Sark carried about 1,500 tonnes, had a crew of 30 and
couldn't use the Suez Canal. The Emma Maersk carries over 150,000
tonnes, has a crew of 13 and does use the Suez Canal.

The point is that steamships were reliably faster, not in best top
speed, but in predictable average speed, and used less crew. So they
were commercially more profitable.

As with all things wind power, everybody thinks that what they COLD do
is what they DID do. On average, clipper ships were by the standards of
a modern motorised vessel, total rubbish on AVERAGE speeds.

With or without the Suez canal.

Remember the heyday of the tea clipper was shangai to san francisco. No
canal in the way there.

The Natural Philosopher wrote:
Peter Parry wrote:
On 30 Apr 2011 21:29:53 GMT, Steve Firth wrote:
The Natural Philosopher wrote:
Average clipper ship speed was a little over a fast walking pace.
A clipper ship could make 17 - 18 knots.

It COULD. But if you bother to learn English, you might see that I said 'average'

If you bothered to remove your head from your arse you will realise that
you did not say that a clipper ship made an average speed a little over
fast walking pace. You stated that the average clipper ship made a speed a
little over fast walking pace.

Perhaps you could learn how to write English?

You're still wrong. Clipper ships averaged 8 knots. A fast walk is not 8
knots.

You could be a man and admit you were wrong, for a change.

ON average, they did not. Due to having to cover huge extra distances in
tacking, or simple lack of wind.

Almost no tacking is require imbibe clipper routes. Stop showing your
ignorance.

In message
,
Steve Firth writes

Almost no tacking is require imbibe clipper routes.


Is there ANYONE here that speekee inggris



--
geoff

geoff wrote:

In message
,
Steve Firth writes

Almost no tacking is require imbibe clipper routes.


Is there ANYONE here that speekee inggris

The iPhone thinks it can speak Ingrish better than I can.

On Apr 30, 11:19*am, The Natural Philosopher
wrote:
tony sayer wrote:
Depends on your definition of 'natural'

and hydrogen is a far worse fuel to
manage than hydrocarbon fuel.

Does the carbon make it slippery or sumfink;?..

No. Lack of carbon makes its molecularly small, putting great stress on
seals. Its odourless and colourless. So its totally invisible till you
light a fag.. Its also bulky. Not in weight, but in size, so while it
has the greatest energy density per unit weight of any chemical fuel,
(why its used in rockets) its got a fairly poor energy density in terms
of space occupied (which is why we use kerosene for jets: which don't
have a lot of space in them for aerodynamic reasons.

If you do the analysis something like diesel/Avjet is in fact about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks. It's got
a fairly high energy density, its molecularly large enough not to seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.

The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Its about the only practicable 'off grid' fuel we have.

That .. was in a roundabout way the reason for pointing it out. What we
of course need is a new portable fuel but that doesn't seem to be
happening anytime soon..

when you look at stored energy, which is what fuel is, we only have so
many technologies that work.

Stressed materials like clockworks springs
Kinetic energy like flywheels
Potential energy like water-up-a-hill.
Heat energy like a red hot lump of metal.
Electrical energy like a battery or a capacitor or a 'charged'
superconducting solenoid.
Chemical energy like a tank of diesel
Nuclear energy like a lb of U-235.

There are no 'new fuels'

There are new ways of applying existing fuel sources as in the
aforementioned redox battery.

MBQ

On 03/05/11 12:19, Man at B&Q wrote:

If you do the analysis something like diesel/Avjet is in fact about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks. It's got
a fairly high energy density, its molecularly large enough not to seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.

The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Thanks, will they post it or do I need to go to Sweden to collect it?

It just needs a slight tweak to existing technology. Destructive
distillation is the process that makes coke and gas from coal. You just
heat it in the absence of oxygen. You can do the same with wood and get
charcoal, we don't usually collect the gas that generates.

If instead of just excluding air you add hydrogen under pressure to the
wood most of the carbon will be released as hydrocarbons. It's going to
need quite high temperatures, in fact about the core temperature of the
new thorium reactors. They will also generate electricity required to
split water into oxygen and the hydrogen required.

The net process is to convert the energy in sunlight and thorium into
hydrocarbons. You could do it without the thorium but it would be less
efficient. It's a carbon-neutral process that will generate high-quality
fuels plus long-chain molecules that can be used to synthesise plastics
etc. You can choose pretty much any type of plant, it doesn't need to be
one that is particularly fast-growing. So it's quite possible for the
system to generate flour and apples as a by-product.




--
Bernard Peek

The Natural Philosopher wrote:
[snip]

No. Lack of carbon makes its molecularly small, putting great stress on seals.


That's a bizarre way of describing hydrogen. It's not "lack of carbon" that
makes hydrogen small, it's simply the fact that hydrogen is the smallest
possible atom. One proton, one electron.

Its odourless and colourless. So its totally invisible till you light a fag..

It's still invisible then, there's not much of a flame from hydrogen.

Its also bulky. Not in weight, but in size, so while it has the greatest
energy density per unit weight of any chemical fuel, (why its used in
rockets) its got a fairly poor energy density in terms of space occupied
(which is why we use kerosene for jets: which don't have a lot of space
in them for aerodynamic reasons.

Kerosene and polyethylene are used as fuel in rockets because of the
superior energy density per unit volume and ease of handling compared to
cryogenic fuels.

If you do the analysis something like diesel/Avjet is in fact about the
best chemical fuel there is for most purposes.

Firstly there's no such fuel as Avjet. Avjet is an aviation company. AVTUR
is the term used for Aviation kerosene which is not the same fuel as
diesel.

And it's not true to say that these are ideal fuels for most purposes. They
are ideal for the use that is made of them. Pure carbon has better energy
density per unit volume and methane is a better fuel for most
non-automotive use.

It's liquid, at most temperatures we encounter.. it's dense and fits in
small tanks. It's got a fairly high energy density, its molecularly large
enough not to seep out of most simple connectors, and its got flash point
that makes it both quite hard to accidentally ignite, but low enough so
that deliberate combustion is not that hard either.

The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Already been done. Blue-green algae, water, sunlight, atmospheric CO2. It's
unlikely that any other route will work out cheaper.

FWIW canola is already competitive with fossil fuel at the point of
production but as a foodstuff its price as a commodity is more volatile
than petroleum.

Its about the only practicable 'off grid' fuel we have.

Hyperbole, again. Why not just stick to facts, and check those facts?

Man at B&Q wrote:
On Apr 30, 11:19 am, The Natural Philosopher
wrote:
tony sayer wrote:
Depends on your definition of 'natural'
and hydrogen is a far worse fuel to
manage than hydrocarbon fuel.
Does the carbon make it slippery or sumfink;?..
No. Lack of carbon makes its molecularly small, putting great stress on
seals. Its odourless and colourless. So its totally invisible till you
light a fag.. Its also bulky. Not in weight, but in size, so while it
has the greatest energy density per unit weight of any chemical fuel,
(why its used in rockets) its got a fairly poor energy density in terms
of space occupied (which is why we use kerosene for jets: which don't
have a lot of space in them for aerodynamic reasons.
If you do the analysis something like diesel/Avjet is in fact about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks. It's got
a fairly high energy density, its molecularly large enough not to seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.
The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..
Its about the only practicable 'off grid' fuel we have.
That .. was in a roundabout way the reason for pointing it out. What we
of course need is a new portable fuel but that doesn't seem to be
happening anytime soon..
when you look at stored energy, which is what fuel is, we only have so
many technologies that work.

Stressed materials like clockworks springs
Kinetic energy like flywheels
Potential energy like water-up-a-hill.
Heat energy like a red hot lump of metal.
Electrical energy like a battery or a capacitor or a 'charged'
superconducting solenoid.
Chemical energy like a tank of diesel
Nuclear energy like a lb of U-235.

There are no 'new fuels'

There are new ways of applying existing fuel sources as in the
aforementioned redox battery.

Indeed. But they can't go beyond the theoretical energy density of the
materials involved, or beyond 100% efficiency.


For example. I calculated that if all 27 million households in the UK,
had ad electric car with a 50KWH lithium battery, at 100% efficiency...

- it would take about half the world total known lithium reserves.
- it would weigh about 6.75 million tonnes
- the combined energy storage would be enough to power the UK grid for
slightly less than two days.

-10,000 tonnes of deplete uranium flywheels one meter across spinning at
100,000 RPM could power the UK grid for slightly less than an hour.


-2000 tonnes of enriched uranium can power the UK grid for about a year
and a half.

You cannot use technology to fix problems that are outside of
technology, and in the realms of physics and chemistry. Technological
analysis may identify ways in which perfect machines may be appraoched,
but never achieved, and machines run on energy, not on mathematics.


We have known about all these energy storage ideas for years, if not
centuries. They haven' failed to achieve the sort of dominance that
fossil fuels have, because of lack of technological smarts. They have
failed because they are inherently inferior as energy storage mediums.

Which is why clock springs replaced weights, and batteries replaced
clock springs. More energy in a smaller and lighter package.

Its why steam power aircraft are dubious at best, whereas petrol and
diesel are not. Steam must carry its water. And have large strong
pressure vessels to make it. IC engines use the air as part of the fuel,
and confine high pressures solely to the combustion chamber itself.

Ergo more power, more range, less weight.

To ate nothing is lighter than a tank of hydrogen, and nothing is
smaller than a tank of diesel when it comes to energy storage that is
faintly usable.

Of course uranium is far better, but it needs a lot of payload to keep
it safe. .

Theoretically a plasma at a few million degrees would work too, if we
could build a sufficiently good thermos flask to hold it. If you do, let
the nuclear fusion boys know. They've only been working on it for 60
years now.

Flywheels are limited my material properties and of course gyro effects.

There is a limit to how fast they can be run before they fly apart under
their own mass.

Ditto springs and rubber bands.

You might consider compressed air. Until you consider the practical
consequences of containment failure.

Energy storage is dangerous, if there is a way it can all get released
at once.

Clock springs snap, shorted capacitors weld or explode, as do shorted
batteries. So can flywheels. Or steam boilers. Tanks of fuel can go
bang, and enough uranium can if very carefully arranged, do likewise.
Even coal dust can explode. Dams can burst.

So within all those basic physical properties, we look for solutions
that fit the application in terms of size, weight, stability, cost and
so on.

It so happens that in rural Africa, clockwork radios are perfect. The
solution fits the conditions.

For aircraft a tank of kerosene is perfect. Its not too flammable, and
gets a lot of power into a relatively simple engine.

Ditto cars.

For fixed location power stations where weight is not an issue, yu can
pick between coal, gas, or nuclear, all are capable of turning stored
energy into controllable reliable power.

Windmills are not capable of turning energy stored in wind into
controllable reliable power, not because the technology is deficient,
but because the source is deficient. That cannot be solved through
technology.








MBQ

Bernard Peek wrote:
On 03/05/11 12:19, Man at B&Q wrote:

If you do the analysis something like diesel/Avjet is in fact about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks. It's got
a fairly high energy density, its molecularly large enough not to seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.
The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Thanks, will they post it or do I need to go to Sweden to collect it?


they wont award it if you are using coal as a feedstock. You have to
start with the CO2.

It just needs a slight tweak to existing technology. Destructive
distillation is the process that makes coke and gas from coal. You just
heat it in the absence of oxygen. You can do the same with wood and get
charcoal, we don't usually collect the gas that generates.

If instead of just excluding air you add hydrogen under pressure to the
wood most of the carbon will be released as hydrocarbons. It's going to
need quite high temperatures, in fact about the core temperature of the
new thorium reactors. They will also generate electricity required to
split water into oxygen and the hydrogen required.

The net process is to convert the energy in sunlight and thorium into
hydrocarbons. You could do it without the thorium but it would be less
efficient. It's a carbon-neutral process that will generate high-quality
fuels plus long-chain molecules that can be used to synthesise plastics
etc. You can choose pretty much any type of plant, it doesn't need to be
one that is particularly fast-growing. So it's quite possible for the
system to generate flour and apples as a by-product.


It wont scale, because if the growing of biomass were the best way to
pull CO2 out of the air, we wouldn't have rising CO2 levels would we?

I repeat, you have water and CO2 and energy. Make hydrocarbons at better
than 50% efficiency.

A nuclear reactor is allowed.

On 03/05/11 16:00, The Natural Philosopher wrote:
Bernard Peek wrote:
On 03/05/11 12:19, Man at B&Q wrote:

If you do the analysis something like diesel/Avjet is in fact
about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks.
It's got
a fairly high energy density, its molecularly large enough not to
seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.
The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Thanks, will they post it or do I need to go to Sweden to collect it?


they wont award it if you are using coal as a feedstock. You have to
start with the CO2.

I'm not. I'm starting with CO2


It just needs a slight tweak to existing technology. Destructive
distillation is the process that makes coke and gas from coal. You just
heat it in the absence of oxygen. You can do the same with wood and get
charcoal, we don't usually collect the gas that generates.

If instead of just excluding air you add hydrogen under pressure to the
wood most of the carbon will be released as hydrocarbons. It's going to
need quite high temperatures, in fact about the core temperature of the
new thorium reactors. They will also generate electricity required to
split water into oxygen and the hydrogen required.

The net process is to convert the energy in sunlight and thorium into
hydrocarbons. You could do it without the thorium but it would be less
efficient. It's a carbon-neutral process that will generate high-quality
fuels plus long-chain molecules that can be used to synthesise plastics
etc. You can choose pretty much any type of plant, it doesn't need to be
one that is particularly fast-growing. So it's quite possible for the
system to generate flour and apples as a by-product.


It wont scale, because if the growing of biomass were the best way to
pull CO2 out of the air, we wouldn't have rising CO2 levels would we?

I don't follow the logic there. I don't see why the process shouldn't
scale up to deliver as much hydrocarbon fuel as we need.


I repeat, you have water and CO2 and energy. Make hydrocarbons at better
than 50% efficiency.

The 50% requirement is hard to reach. Photosnthesis is the most
efficient process we know of and it's less than 20% efficient under
ideal conditions. The route via biomass to fossil-fuel is much less
efficient than that. It starts with photosynthesis and then throws away
99.99% of the product.

My process could probably manage an efficiency of about 10% and I'd
consider that to be a major success.



--
Bernard Peek

Bernard Peek wrote:
On 03/05/11 16:00, The Natural Philosopher wrote:
Bernard Peek wrote:
On 03/05/11 12:19, Man at B&Q wrote:

If you do the analysis something like diesel/Avjet is in fact
about the
best chemical fuel there is for most purposes. It's liquid, at most
temperatures we encounter.. it's dense and fits in small tanks.
It's got
a fairly high energy density, its molecularly large enough not to
seep
out of most simple connectors, and its got flash point that makes it
both quite hard to accidentally ignite, but low enough so that
deliberate combustion is not that hard either.
The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..
Thanks, will they post it or do I need to go to Sweden to collect it?

they wont award it if you are using coal as a feedstock. You have to
start with the CO2.

I'm not. I'm starting with CO2

It just needs a slight tweak to existing technology. Destructive
distillation is the process that makes coke and gas from coal. You just
heat it in the absence of oxygen. You can do the same with wood and get
charcoal, we don't usually collect the gas that generates.

If instead of just excluding air you add hydrogen under pressure to the
wood most of the carbon will be released as hydrocarbons. It's going to
need quite high temperatures, in fact about the core temperature of the
new thorium reactors. They will also generate electricity required to
split water into oxygen and the hydrogen required.

The net process is to convert the energy in sunlight and thorium into
hydrocarbons. You could do it without the thorium but it would be less
efficient. It's a carbon-neutral process that will generate high-quality
fuels plus long-chain molecules that can be used to synthesise plastics
etc. You can choose pretty much any type of plant, it doesn't need to be
one that is particularly fast-growing. So it's quite possible for the
system to generate flour and apples as a by-product.

It wont scale, because if the growing of biomass were the best way to
pull CO2 out of the air, we wouldn't have rising CO2 levels would we?

I don't follow the logic there. I don't see why the process shouldn't
scale up to deliver as much hydrocarbon fuel as we need.

Because at 10%, the incident sunlight times the available land area (not
used for food) is less than the energy we need to run society?

You cannot use sunlight to do the primary hydrocarbon fix. There is not
enough of it.

Now if you are talking nuclear powered lights in huge underground cave-
forests..I might be more sympathetic.

It looks like the toughest nut to crack is CO2-hydrocarbon. After that
it's relatively simple.

What I am saying is that we use about 1% of the energy that falls on us
as fossil energy to run everything. Biomass captures about 0.5%. so
there is never going to be enough energy even if we harvest every single
growing thing, to meet that.

And that means we don't grow anything for food.

So the primary problem is to take water, nuclear energy, and CO2 and
make hydrocarbons.

Do THAT at sane efficiencies, and you will be richer than Bill Gates if
you patent it.

I suspect actually the best approach is artificially lit hydroponics and
green algae.

On 03/05/11 16:32, The Natural Philosopher wrote:

It wont scale, because if the growing of biomass were the best way to
pull CO2 out of the air, we wouldn't have rising CO2 levels would we?

I don't follow the logic there. I don't see why the process shouldn't
scale up to deliver as much hydrocarbon fuel as we need.

Because at 10%, the incident sunlight times the available land area (not
used for food) is less than the energy we need to run society?

You cannot use sunlight to do the primary hydrocarbon fix. There is not
enough of it.

There certainly won't be enough if the current third-world countries
start to demand the same amount of energy that we use, but I think it's
possible to meet current energy demands. If energy demands increase then
photosynthesis in orbit is the best sustainable plan, and I've figured
out a new angle on that too if anyone is interested.

Sustainable solutions (that is not using fossil fuels like thorium) will
require a much lower population, less than 1bn worldwide and also more
efficient energy use.


Now if you are talking nuclear powered lights in huge underground cave-
forests..I might be more sympathetic.

It looks like the toughest nut to crack is CO2-hydrocarbon. After that
it's relatively simple.

I believe that there's an electrolytic method that requires some exotic
solvent.


What I am saying is that we use about 1% of the energy that falls on us
as fossil energy to run everything. Biomass captures about 0.5%. so
there is never going to be enough energy even if we harvest every single
growing thing, to meet that.

We can certainly open up some more areas for cultivation although that's
going to require us to wipe out some habitats, like the Sahara.


And that means we don't grow anything for food.

So the primary problem is to take water, nuclear energy, and CO2 and
make hydrocarbons.

Do THAT at sane efficiencies, and you will be richer than Bill Gates if
you patent it.

I suspect actually the best approach is artificially lit hydroponics and
green algae.

Yes, but I thought of doing that in orbital stations fed by sunlight and
the Oort cloud.



--
Bernard Peek

Tim Streater wrote:
In article
,
Steve Firth wrote:


Kerosene and polyethylene are used as fuel in rockets because of the
superior energy density per unit volume and ease of handling compared to
cryogenic fuels.

Why did the Shuttle external tank use O2 and H2?


Because hydrogen has the best energy density by WEIGHT,.

Kerosene is about the best BY VOLUME

Volume is more important in aircaft, weigth is all in a rocket.



[snip]

The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Already been done. Blue-green algae, water, sunlight, atmospheric CO2.
It's
unlikely that any other route will work out cheaper.

Could this be done on an industrial scale, then, using light supplied by
Nuclear volts? We need to do it in this country, not the Sahara.


Maybe.
FWIW canola is already competitive with fossil fuel at the point of
production but as a foodstuff its price as a commodity is more volatile
than petroleum.

I take it by Canola you are referring to rapeseed oil?

Its the agribusiness name for it, yes.

Its only competitive because of high fuel taxes tho,.

On 03/05/11 17:48, The Natural Philosopher wrote:


Why did the Shuttle external tank use O2 and H2?


Because hydrogen has the best energy density by WEIGHT,.

Kerosene is about the best BY VOLUME

Volume is more important in aircaft, weigth is all in a rocket.

The weight of the storage apparatus is also important. On the ground a
hydrogen tank can be refrigerated by an external plant. In space if you
have to have the cooling plant along you lose the mass advantage. That's
why hydrogen is only used for rockets that get used up in getting into
orbit and not always then.


--
Bernard Peek

Tim Streater wrote:


Kerosene and polyethylene are used as fuel in rockets because of the
superior energy density per unit volume and ease of handling compared to
cryogenic fuels.

Why did the Shuttle external tank use O2 and H2?

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?

[snip]

The man who comes up with a cheap energy efficient way to synthesise
diesel, from water and CO2, will be awarded a Nobel Prize..

Already been done. Blue-green algae, water, sunlight, atmospheric CO2. It's
unlikely that any other route will work out cheaper.

Could this be done on an industrial scale, then, using light supplied by
Nuclear volts? We need to do it in this country, not the Sahara.

It would be the wrong way to do things IMO. Politically anything that
fosters international trade and gives a country with no much more than
sunlight a chance of an income is fine by me. And if one wanted to use
nuclear to produce hydrocarbons from feedstock I'm sure there are more
efficient means to do so than using sunlamps to grow algae. Algae farms
work well at harvesting sunlight and that, IMO, is how they should be
used.

FWIW canola is already competitive with fossil fuel at the point of
production but as a foodstuff its price as a commodity is more volatile
than petroleum.

I take it by Canola you are referring to rapeseed oil?

Yes.

The Natural Philosopher wrote:

Tim Streater wrote:
In article
,
Steve Firth wrote:


Kerosene and polyethylene are used as fuel in rockets because of the
superior energy density per unit volume and ease of handling compared to
cryogenic fuels.

Why did the Shuttle external tank use O2 and H2?


Because hydrogen has the best energy density by WEIGHT,.

Do you think that putting words in CAPITALS makes you look clever, or
DUMB?

Kerosene is about the best BY VOLUME

Not even close. Aluminium and carbon (anthracite) are better.

Volume is more important in aircaft, weigth is all in a rocket.

Go on then, explain why solid boosters and hybrids are so popular in
rocketry if, as you say, weight is "all" in a rocket. Indeed perhaps you
can explain why the Space Shuttle gets most of the way into space
boosted by two solid rocket motors that provide the majority of the
thrust.

[snip]

I take it by Canola you are referring to rapeseed oil?

Its the agribusiness name for it, yes.

Its only competitive because of high fuel taxes tho,.

Untrue. It is inherently competitive and can be grown for £0.25 per
litre - better than the price of fossil oil and cheap enough to be
considered as a fuel. The problem is economic, the price of rapeseed oil
is now linked closely to the price of petroleum because it can be used
as a fuel and it is also subject to the usual variations to be expected
for a food commodity. As was previously explained or EXPLAINED if you
prefer.

Huge wrote:
[snip]

Can I seize this opportunity to recommend one of the best books I've
ever come across;

"Ignition! An informal history of liquid rocket propellants" by John D. Clark.

http://library.sciencemadness.org/li...s/ignition.pdf

I borrowed a copy from a colleague many years ago and despaired of ever
finding one of my own, especially since paper copies sell for ridiculous
amounts of money; $400+

Excellent, thanks.

If you don't already have it, I recommend "The Golden Book of Chemistry
Experiments" by Robert Brent. There was a copy in the Library of one of
the primary schools that I attended. It's what got me into science in
general and chemistry in particular.

http://chemistry.about.com/library/goldenchem.pdf

Apparently it was banned for being too interesting for its own good.

On 22/04/2011 21:14, tony sayer wrote:
What you need is a car that runs on Rechargable DDDDDDDDD Cells. As they
get low you pull into the filling station where your set are ejected and
begin recharge, and a fully charged set are installed. In 30 hours time,
your ejected set can be rotated into the next car that pulls in.


What we really need is to dump the idea of batteries, and work on a more
efficient heat engine or fuel cell for the primary power.


Maybe, but there's quite a bit of work going on investigating the
opportunities for a large number of electric vehicles providing mass
storage for generated electricity (see "Windfarms paid to shut down").

Cars connected up to car-park charging units during the day acting as a
national resource for storage of electrical energy. Then driven home and
connected to the charging units there, where their stored charge can be
used to top up the evening peak demand, with the drawn charge 'repaid'
later in the night.

"Steve Firth" wrote in message
.. .

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?

That would be because its difficult to mix the O2 and H2 fast enough in a
controlled manner to get the same thrust as you can get from burning the
solid propellant (which isn't all aluminium BTW).

On 03/05/2011 19:14, Steve Firth wrote:

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?


I could be wrong, but I've heard that internal politics - having the
work done in the right congressman's area - was a significant factor in
the Morton Thiokol contract.

After all what sensible engineer would have chosen to build the SRBs in
sections?

Andy

Andy Champ wrote:
On 03/05/2011 19:14, Steve Firth wrote:

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?


I could be wrong, but I've heard that internal politics - having the
work done in the right congressman's area - was a significant factor in
the Morton Thiokol contract.

After all what sensible engineer would have chosen to build the SRBs in
sections?


One that has to transport them across several states to get them to teh
launch site.

Solid fuel is simpler but completely uncnotrollable.

I used as pure grunt because its cheap and simple. Shame they couldn't
even get a couple of fireworks right.. The controlled stuff is done with
liquid fuels.

Don't bother with firth**** tho. Kill fill the arrogant cnut.

Andy

Andy Champ wrote:

On 03/05/2011 19:14, Steve Firth wrote:

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?


I could be wrong, but I've heard that internal politics - having the
work done in the right congressman's area - was a significant factor in
the Morton Thiokol contract.

After all what sensible engineer would have chosen to build the SRBs in
sections?

And which congressman has Air Products in his area?

Tim Streater wrote:
In article ,
Andy Champ wrote:

On 03/05/2011 19:14, Steve Firth wrote:

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?


I could be wrong, but I've heard that internal politics - having the
work done in the right congressman's area - was a significant factor
in the Morton Thiokol contract.

After all what sensible engineer would have chosen to build the SRBs
in sections?

Aren't they shipped by rail (at least for part of the journey)? AIUI,
the diameter is the fault of the Romans and/or the size of a horse's
arse, but perhaps the length of the sections is determined by what they
could get through curved railway tunnels.

A story I saw first on the Good, Clean Funnies List.

http://gcfl.net/archive.php?funny=428

--
Tciao for Now!

John.

Tim Streater wrote:
In article ,
(Steve Firth) wrote:

Untrue. It is inherently competitive and can be grown for �0.25 per
litre - better than the price of fossil oil and cheap enough to be
considered as a fuel.

What is the yield per acre?

its on-line somewhere..i did this calc a few years back... 30 tonnes maybe?

Its actually not directly competitive, but various subsidies and tax
dodges make it so.Nowhere near enough prime land to grow more than a
token amount of course, but token amounts are what placates greeniots,
and that's what matters.

Tim Streater wrote:

In article ,
(Steve Firth) wrote:

Untrue. It is inherently competitive and can be grown for ?0.25 per
litre - better than the price of fossil oil and cheap enough to be
considered as a fuel.

What is the yield per acre?

Quoted as 460 litres/acre which is slightly less than I get from olives
which produce around 470 litres/acre, but with much less manual labour
than olives which need to be pruned twice a year and then need to be
picked manually. I understand that rapeseed also produces much less
by-product in the form of must and pomace than olive. Disposing of olive
waste is a serious problem, although we burn the pomace for fuel. The
major problem with pomace as a fuel is that it burns much hotter than
wood so needs a specially constructed furnace.

I think we could get the yield of olive oil up if we were to steam crack
the kernels and pomace to extract the remaining oil - known as lampante
because it used to be used to fuel oil lamps. However I'm guessing that
steaming the oil out of waste is unlikely to make sense in terms of
energy input.

The olives also produce a decent amount of wood for the fire - I haven't
bothered to work that out in terms of yield per acre, but it's
significant we could provide all our heating needs from pruning alone.
So about 200Kg per acre, I guess.

Tim Streater wrote:

In article ,
"dennis@home" wrote:

"Steve Firth" wrote in message
.. .

Or alternatively why were the solid boosters, which provide most of the
thrust up to 150,000 feet and that burn aluminium as a fuel necessary?

That would be because its difficult to mix the O2 and H2 fast enough in a
controlled manner to get the same thrust as you can get from burning the
solid propellant (which isn't all aluminium BTW).

The fuel is largely aluminium, the other components are a polymer binder
and the oxidiser.

Solid fuel boosters are a bit light-the-blue-touch-paper, of course.

They don't have to be though. A hybrid uses a solid fuel and (usually)
an oxidiser that is a gas. These engines can be turned on and off in
flight.

The Natural Philosopher wrote:

Don't bother with firth**** tho. Kill fill the arrogant cnut.

Says the arrogant, and frequently wrong, ****.

Wassup TNP, peeved to be proved wrong, again?

"The Natural Philosopher" wrote in message
...
Andy Champ wrote:


After all what sensible engineer would have chosen to build the SRBs in
sections?


One that has to transport them across several states to get them to teh
launch site.

Not the reason..
the military launches used single section boosters as they were lighter and
allowed more payload.

They couldn't be recovered and reused.

On 04/05/2011 20:09, The Natural Philosopher wrote:
OG wrote:
On 22/04/2011 21:14, tony sayer wrote:
What you need is a car that runs on Rechargable DDDDDDDDD Cells. As
they
get low you pull into the filling station where your set are ejected
and
begin recharge, and a fully charged set are installed. In 30 hours
time,
your ejected set can be rotated into the next car that pulls in.


What we really need is to dump the idea of batteries, and work on a more
efficient heat engine or fuel cell for the primary power.


Maybe, but there's quite a bit of work going on investigating the
opportunities for a large number of electric vehicles providing mass
storage for generated electricity (see "Windfarms paid to shut down").


well you should have followed my discourses there.

Why?

In short, 25% of the world total known lithium reserves would keep the
UK grid going for 45 hours if put into 27 million cars.


Cars connected up to car-park charging units during the day acting as
a national resource for storage of electrical energy. Then driven home
and connected to the charging units there, where their stored charge
can be used to top up the evening peak demand, with the drawn charge
'repaid' later in the night.


It's utter greenwash, as the figures above show.

Do they?

Huge wrote:

Nostalgia's not what it was.

And it never will be.

On 03/05/11 23:26, Tim Streater wrote:


What could we expect from the algae/sunlight approach? I'd be curious to
know whether using big chunks of the Sahara could provide useful
amounts. Hmmm, taking 500l/acre, a square of land 100 by 100 miles would
provide 3.2 billyun litres. Whether enough CO2 would diffuse in is an
interesting question.

Current biofuel projects only get back a small fraction of the carbon
captured because they only use the oil/seed of the plant. My suggested
process turns the whole plant into hydrocarbon fuel. The algae/sunlight
approach gets you solid biomass that would probably be eaten or burned.
Alternatively you could feed it into my system and get back all of the
carbon as fuel oils or whatever other hydrocarbon you want.

--
Bernard Peek

OG wrote:
On 22/04/2011 21:14, tony sayer wrote:
What you need is a car that runs on Rechargable DDDDDDDDD Cells. As they
get low you pull into the filling station where your set are ejected and
begin recharge, and a fully charged set are installed. In 30 hours time,
your ejected set can be rotated into the next car that pulls in.


What we really need is to dump the idea of batteries, and work on a more
efficient heat engine or fuel cell for the primary power.


Maybe, but there's quite a bit of work going on investigating the
opportunities for a large number of electric vehicles providing mass
storage for generated electricity (see "Windfarms paid to shut down").


well you should have followed my discourses there.

In short, 25% of the world total known lithium reserves would keep the
UK grid going for 45 hours if put into 27 million cars.


Cars connected up to car-park charging units during the day acting as a
national resource for storage of electrical energy. Then driven home and
connected to the charging units there, where their stored charge can be
used to top up the evening peak demand, with the drawn charge 'repaid'
later in the night.


It's utter greenwash, as the figures above show.

The Natural Philosopher wrote:

In short, 25% of the world total known lithium reserves would keep the
UK grid going for 45 hours if put into 27 million cars.

WikiP reckons all the world lithium would produce batteries for 2
billion cars, but whichever, after 10ish years they'll be knackered,
rinse & repeat until no more lithium left ... or hope people remember to
recycle it?

Andy Burns wrote:
The Natural Philosopher wrote:

In short, 25% of the world total known lithium reserves would keep the
UK grid going for 45 hours if put into 27 million cars.

WikiP reckons all the world lithium would produce batteries for 2
billion cars, but whichever, after 10ish years they'll be knackered,
rinse & repeat until no more lithium left ... or hope people remember to
recycle it?

I made it no more than 100 million.

Maybe their batteries were smaller.


Probably written by a green sock puppet then.

OG wrote:
On 04/05/2011 20:09, The Natural Philosopher wrote:
OG wrote:
On 22/04/2011 21:14, tony sayer wrote:
What you need is a car that runs on Rechargable DDDDDDDDD Cells. As
they
get low you pull into the filling station where your set are ejected
and
begin recharge, and a fully charged set are installed. In 30 hours
time,
your ejected set can be rotated into the next car that pulls in.


What we really need is to dump the idea of batteries, and work on a
more
efficient heat engine or fuel cell for the primary power.


Maybe, but there's quite a bit of work going on investigating the
opportunities for a large number of electric vehicles providing mass
storage for generated electricity (see "Windfarms paid to shut down").


well you should have followed my discourses there.

Why?

In short, 25% of the world total known lithium reserves would keep the
UK grid going for 45 hours if put into 27 million cars.


Cars connected up to car-park charging units during the day acting as
a national resource for storage of electrical energy. Then driven home
and connected to the charging units there, where their stored charge
can be used to top up the evening peak demand, with the drawn charge
'repaid' later in the night.


It's utter greenwash, as the figures above show.

Do they?
To intelligent people. yes.