Posted on 08/13/2005 3:42:35 AM PDT by Arkie2
Or, as I think it was Larry Niven who pointed it out first, we can use parts of the Nevada Test Site to dispose of the radioactive waste from temporary increased use of nuclear-fission for power generation [until we get SPS or fusion or something else thats better]...aferall what less harmful place to put nuclear waste could there be than down a selected-for-geological-stability and already-radio-contaminated old bomb-hole ?
Several years ago I read an article which mentioned that one of the bigger issues with large-scale solar facilities was simple *dust* and dirt and pollen, etc. Over time it builds up on the mirrors/lenses/solarcells/whatever, and you have to send out a freaking huge army of window washers on a regular basis to keep , or work out some automatic system of cleaning the collectors. Either way, you have to budget a surprisingly large amount for maintenance operations, plus probably a heck of a lot of water for the washing, and likely a soap or other cleaning solution as well. Now you've got drainage and run-off to worry about, and environmental effects, and...
"Tests conducted by SCE and the Sandia National Laboratories
have shown that the Stirling dish technology is almost twice as
efficient as other solar technologies."
I think this is a wonderful idea. The stirling engine is an amazing motor.
It makes a neat little model. The stirling engine below runs on the heat
from your hand.
Holtz
JeffersonRepublic.com
I wonder why they switched to hydrogen???
My guess would be cost.
Yeah, your "ounce for ounce" weasel-word lets you out. But on a mole for mole basis (which is what the entire rest of the world uses) hydrocarbons contain more energy than hydrogen.
"C chain fuel in a rocket has a lower ISP than H2 because the C bonds are not proportionally stronger than H bonds compared to their weight."
Sorry, but wrong again. Carbon has a lower specific impulse than hydrogen because the mass of the molecule formed and ejected is lower. It has squat to do with the "strength of the carbon bonds".
"Chemistry happens to the electrons bonds and not all electrons in C and other heavier elements are involved in bonds. So they are carrying a lot of nuclear dead weight."
Uh, PhD in chemistry--minor in Nuclear Science.
RE: mirrors, dust, etc.
Seems like a lot of coatings and materials research should go into how to make the mirrors plus maybe some sort of static dust repulsion system could be built-in.
Yes, but you're not going to get a significantly higher exhaust velocity with any chemical fuels--there's simply not enough difference in energy. Reducing the average exhaust mass of the ejected propellant is a LOT easier than increasing the exhaust velocity in a chemically reactive system. Only ONE chemical fuel combination has a higher specific impulse then H2-02--an exotic propellant using hydrogen, lithium, and fluorine. Now, in things like "ion drives", where the absolute speed of the "heavier" propellant is VASTLY higher, then yes, you can get usably higher ISP's with propellants with higher mass values.
And in fact, there's still a lot of argument that H2-O2 is NOT the best propellant choice, for various other reasons (like safety).
"Time for a refresher course, me thinks."
No, actually it comes from trying to winnow down complex processes into simple terminology. Spend a little time on the Wikipedia "rocket propulsion" page and see how complex it really is.
Would you please provide a link for that statement? To the best of my knowledge, Stirlings don't replace Otto cycle engines in automotive applications because they take longer to start, run at much higher RPMs, are bulkier and aren't suited to the variable power that automobiles demand.
A power plant, however, seems like a made-to-order application for Stirling engines.
On the other hand, newer Hybrids are using Atkinson-cycle engines to get greater efficiency from a gasoline engine at the expense of power. They're more complex because the pistons are connected to the crankshaft via a series of levers instead of directly as in the Otto cycle. This allows the engine to run with a longer power stroke, hence the efficiency gain.
I second your opinion.
For something different: A perpetual motion machine:
http://www.freerepublic.com/focus/f-news/1463214/posts
What? Atkinson would be turning over in his grave! Toyota and others are telling a lie to get around the Miller cycle patents that they really use. No extra connecting rods in these engines, just a late closing intake valve.
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