[Space Frontier Foundation Logo]

The Space Arena Board

§ [Start a New Thread] § [Help and Hints] § [Archives] §

Re: Lesson's learned: How to make SEI successful
<<Prev | 3075 of 19696 | Next>>

Posted by Dennis Wingo (wingod@nailcity.com) at 01:37 GMT on 05 Apr 2004

In reply to Re: Lesson's learned: How to make SEI successful
from Jim Davis at 22:20 GMT on 04 Apr 2004

>I would support a crash program to transition from an internal
>combustion engine driven society that is 25% efficient to a PGM fuel
>cell based infrastructure that is 53% efficient with promise of 75%
>efficiency in conversion of hydrocarbon to propulsive power. In
>order to do this AND not get entangled in Africa for the PGM
>resources it would behoove us to get them from the Moon. No pesky
>dictators to placate, bribes to be given, or people getting money
>that basically hate the west.

You really need to educate yourself on internal combustion engines. The following link:

http://www.sdia.or.jp/mhikobe-e/products/diesel/sulineup.html

has a list of internal combustion engines commercially available each of which is over 50% efficient.

***************

Jim

How do I say this, No it does not. The maximum POSSIBLE efficieny of an internal combusion engine is limited by the laws of thermodyanamics to about 59%. The BEST Diesel engine ever made made it to 52% and that was a 90,000 horsepower model. If you are going to contradict me at least use good data. Standard gasoline engines these days are between 25 and 30% efficient.

Here is from: http://ecen.com/content/eee7/motoref.htm

The value found for the limit efficiency is coherent with other data. If we consider one Carnot Cycle between the adiabatic combustion temperature of gasoline (2,300 K) and the admitted working temperature for steel (925 K), the expected efficiency would be 59%. The largest efficiency already attained, in maritime Diesel engine with 90,000 HP is 52%. In Otto Cycle engines, which use C gasoline (with anhydrous alcohol), it reaches 32% and those which use hydrated alcohol reach 38%.On the other hand, if we consider efficiency as an exclusive function of the compression ratio, the hydrated alcohol engine, with compression ratio of 12 l should reach 52.5%. Therefore, one can notice that there still is a considerable margin for engine development, not sufficient to compensate for the petroleum extraction decline but still significant in terms of fuel saving and reduction of CO 2 and atmospheric pollutants emission ( CO, HC, Nox, aldehydes, etc.) The possibility of using the ternary mixture gasoline - alcohol - water, already demonstrated in preliminary experiments, will allow for combining gasoline and alcohol as a transition fuel for future solutions ( including the hydrated alcohol itself), combining the calorific properties of the former with the anti-knocking properties of alcohol and of water. It is probable that the development of internal combustion engine will be oriented by more refined analysis of the respective thermodynamic cycles. Comparing the expected efficiency for Otto Cycle engine, calculated as an exclusive function of the compression ratio, with efficiency measured in engines using the present technology, one can notice a large difference, demonstrating the inadequacy of the model used in analyzing the cycle, based exclusively on the Energy Conservation Principle. The possible refinement, at first sight, would stem from considering the irreversibility of real transformations undergone by the fuel mixture ( Second Law of Thermodynamics).

>This is where the linkage is made between the broader economy and a >Return to the Moon.

Your linkage is based on your oft stated but mistaken notion that internal combustion engines are limited to 25% efficiency?

Laf. Yep. You need more data to prove me wrong. That site you showed only showed output, none of them the thermodynamic efficiency. THAT is the critical parameter governing the utilization of fuel to power.

>I get ticked off every time I fill up with gas now.

Really? Back in 1973 when you were paying twice what you are now in real terms for gasoline and had to wait in line for an hour and a half for it did you feel good about it because none of it was coming from the middle east?

*************

In 1973 I was 13 years old and we paid 43 cents a gallon for gas. At that time domestic production as much higher as a percentage of total used than now. We got 28% from foreign sources and it is over 50% now. Yes I do feel better when my gas money goes to Texas rather than to Saudi Arabia. That is a dumb question.

>Every time you do so think about how many more soldiers will
>eventually have to die to secure these resources.

Okay, I'll bite. How many soldiers will eventually have to die to secure these resources? So far oil producing countries seem to be quite willing to sell their product on the open market and on the occasions when they haven't (the 1973 embargo) the US has not been inclined to force them to do so.

*******************

To have this attitude shows your depth of lack of understanding of the strategic issue. Last time I checked the gas price in most places in this country are over $2.00 a gallon. The middle east sits on the vast majority of the remaining oil on this planet. Today we have a diversification because we get a lot of our oil from other countries rather than the middle east. As those suppliers reserves are pumped out more and more the nations of the world will compete for more and more scarce middle east oil. You figure it out from here.

>I would much
>rather spend these resources in a way that creates wealth here in
>the U.S. as well as drive our technology firmly into the 21st >century.

Can you demonstrate that wealth *will* be created by your proposals?

1. Methane Ice harvested by American companies from off the North American continental shelf. This methane, used in fuel cells which are twice as efficient as internal combustion engines, allows auto vehicles to first be weaned from oil, which is half of the demand and the cost in this country.

2. A domestic fuel cell industry, enabled by inexpensive quanties of PGM's allows cost effective fuel cell engines to compete in the market with internal combustion engines.

3. We export the finished goods that these technologies bring to other nations, who driven by the need to comply with the Kyoto accords, readily buy our products.

4. Also, the advances in robotics that the return to the Moon generates moves us to the front of that expanding market as well.

yea that is wealth generation.

>If there is a prize, it happens at a level above NASA and frees any
>participant from a government favored architecture and the Federal
>Acquistion Regulations. People who have not had to live under them
>have no idea how screwy they force a business to run.

But if your proposals create wealth what is the purpose of the prize?

*****************************

A prize is like a catalyst in a chemical reaction. It brings the cost of initiation down to a level that is then platable to private enterprise to place capital at risk to reap the rewards. Venture capital is actually very conservative until the herd starts to move. Right now the VC herd is wandering around in circles wondering where to put their money. This is the place, but only if a clear value for the early risk takers is in front of them.

Dennis

Jim Davis

<<Prev | 3075 of 19696 | Next>>
Follow-Ups: