[malcomatic_51]

Here is an article from what appears to be a reputable scientific publication. The abstract of it givn here is little more than drivelling propaganda:

http://www.physorg.com/news101391900.html

It makes comparisons between current jet engines and electric motors that suggest the writer does not understand the difference between a prime mover and secondary motive plant. The jet engine is the prime mover because it produces power from some other type of energy The electric motor is secondary motive plant because something else must produce the power it needs to function. So to say that the superconducting electric jet will be "three times more efficient" is misleading, because it will not be generating its own power.

The article claims that H2 is four times greater in energy density than kerosene. I don't think that's true. If you include the larger tankage space and need for thermal insulation then a hydrogen plane is less efficient than a kerosene plane, as I understand it.

Finally we get into the la-la territory of the Hydrogen Economy and "warm water exhaust". Awwww.... in't that sweet. No mention of the size and efficiency and cost of the fuel cell prime mover. No mention of the trivial detail of where you get the hydrogen from.

Natural gas did you say? Don't be a spoil-sport.

When I see an article like thisit makes me wonder if we won't dissolve into a collective senility rather than face the realities of oil shortages.

[Olle]

I tend to agree with you, but at the same time; If there is one use for H2 in the transport bussiness of the future that would be for airliners. Can't see aeroplanes crossing the Atlantic on lithium-ion batteries. The bad energy returns on using H2 will be something we have to live with if we are to fly at all.

[Graeme]

There will also be superconducting ships!

$this->bbcode_second_pass_quote('', 'F')ortunately, German engineering giant Siemens thinks it can get around such problems. It has designed a motor that uses high-temperature superconductors which only need to be cooled to about -140°C or so. The motor is also placed inside a pod that sits directly beneath the ship, so it is almost completely surrounded by seawater. This allows heat to dissipate far more efficiently, keeping the motor at the required temperature.

[Judgie]

$this->bbcode_second_pass_quote('Graeme', 'T')here will also be superconducting ships!

$this->bbcode_second_pass_quote('', 'F')ortunately, German engineering giant Siemens thinks it can get around such problems. It has designed a motor that uses high-temperature superconductors which only need to be cooled to about -140°C or so. The motor is also placed inside a pod that sits directly beneath the ship, so it is almost completely surrounded by seawater. This allows heat to dissipate far more efficiently, keeping the motor at the required temperature.

[cube]

$this->bbcode_second_pass_quote('', 'I')n contrast, a superconducting motor would be very lightweight and far more efficient electrically, generating three times the torque of a conventional electric motor for the same energy input and weight.

[Tanada]

$this->bbcode_second_pass_quote('malcomatic_51', 'H')ere is an article from what appears to be a reputable scientific publication. The abstract of it givn here is little more than drivelling propaganda:

http://www.physorg.com/news101391900.html

It makes comparisons between current jet engines and electric motors that suggest the writer does not understand the difference between a prime mover and secondary motive plant. The jet engine is the prime mover because it produces power from some other type of energy The electric motor is secondary motive plant because something else must produce the power it needs to function. So to say that the superconducting electric jet will be "three times more efficient" is misleading, because it will not be generating its own power.

The article claims that H2 is four times greater in energy density than kerosene. I don't think that's true. If you include the larger tankage space and need for thermal insulation then a hydrogen plane is less efficient than a kerosene plane, as I understand it.

Finally we get into the la-la territory of the Hydrogen Economy and "warm water exhaust". Awwww.... in't that sweet. No mention of the size and efficiency and cost of the fuel cell prime mover. No mention of the trivial detail of where you get the hydrogen from.

Natural gas did you say? Don't be a spoil-sport.

When I see an article like thisit makes me wonder if we won't dissolve into a collective senility rather than face the realities of oil shortages.

[Andy]

We need to get our facts correct. Kerosene has 4 times the energy density of LH2 by volume and about 1/3 the energy density by unit mass. This could be advantageous for hydrogen in long haul aircraft but not for short haul aircraft as the aircraft would likely be lighter. thanks to lower fuel weight. This is counteracted somewhat however by the need for heavier tanks.

[patrick_b]

Ok, let's face it: the hydrogen economy looks more and more like a hoax. The only people promoting this concept seem to have no basic technical knowledge....


$this->bbcode_second_pass_quote('', 'I') tend to agree with you, but at the same time; If there is one use for H2 in the transport bussiness of the future that would be for airliners. Can't see aeroplanes crossing the Atlantic on lithium-ion batteries.

[cube]

$this->bbcode_second_pass_quote('patrick_b', '.')..
$this->bbcode_second_pass_quote('', 'I')n contrast, a superconducting motor would be very lightweight and far more efficient electrically, generating three times the torque of a conventional electric motor for the same energy input and weight.

[advancedatheist]

Talk about grasping at straws. I suspect we'll see more of this gee-whiz wishful thinking as the transportation situation looks increasingly untenable.

$this->bbcode_second_pass_quote('malcomatic_51', 'H')ere is an article from what appears to be a reputable scientific publication. The abstract of it givn here is little more than drivelling propaganda:

http://www.physorg.com/news101391900.html

[Aimrehtopyh]

$this->bbcode_second_pass_quote('Graeme', 'T')here will also be superconducting ships!

$this->bbcode_second_pass_quote('', 'F')ortunately, German engineering giant Siemens thinks it can get around such problems. It has designed a motor that uses high-temperature superconductors which only need to be cooled to about -140°C or so. The motor is also placed inside a pod that sits directly beneath the ship, so it is almost completely surrounded by seawater. This allows heat to dissipate far more efficiently, keeping the motor at the required temperature.

[Twilight]

$this->bbcode_second_pass_quote('Aimrehtopyh', 'B')ut if you can only do this by heaping on the technical complexity you'll be screwed when the zombies shatter your parts supply chain.

[patrick_b]

$this->bbcode_second_pass_quote('Aimrehtopyh', '')$this->bbcode_second_pass_quote('Graeme', 'T')here will also be superconducting ships!

You might find this interesting:
http://www.amsuper.com/products/motorsG ... ulsion.cfm

What you guys were saying about the impossibility of "tripling" an electric motors efficiency is true but don't forget that on boats and planes weight can be a very important factor when figuring efficiency.

if 1000horsepower+1000pounds+98%efficiency=good enough
then 1000horsepower+ 500pounds+98%efficiency=worlds more payload capacity.

But if you can only do this by heaping on the technical complexity you'll be screwed when the zombies shatter your parts supply chain.

Maybe they meant that the superconducting plane (piloted by pigs, no doubt) would be three times more economical. Step one: collect superconductors. Step two......
Step three: PROFIT.

[Gazzatrone]

$this->bbcode_second_pass_quote('malcomatic_51', 'S')uperconducting jets to save us! - yeah!