Tuesday, May 31, 2011

End of May Update

My Mars mission study has been accepted for presentation at the Mars Society convention in Grapevine, Texas, August 4-7 this year. I will barely be back on my feet after knee surgery at that time, but I wouldn’t miss this meeting on a bet. The basic study was posted here 12-20-10, with an update posted 1-8-11, correcting an error I made in a Falcon-9 payload number.

All of the launcher and capsule data I used were obtained from the Spacex website for 2010. Sometime after January 2011, Spacex updated these data, showing a significant increase in payload capacity estimated for the Falcon-9-heavy, which is now supposed to fly for the first time out of Vandenburg late this year. That change just makes my design even more cost-effective, but I am not going to change my presentation because of it.

I did a little nontraditional thinking, dominated by crew safety, and came up with a tremendous science return for a lot less investment than anyone will likely believe. This is way more than “flag-and-footprints”. You never know what you can do until the blinders come off. It is going to be a lot of fun.

Latest news releases in AAAS’s peer-reviewed “Science” journal confirm everything I posted here about the nuclear plant disaster in Fukushima, Japan. You have to go inside the reactor building ruins before you find radiation too dangerous for adult humans, and then it’s just barely enough to cause prompt radiation sickness. The whole argument over risk to the Japanese public seems to center on the putative risks of very low-level exposures. With no evidence to support or deny a very slight risk of slightly-above-background-level exposures, it seems rather silly to worry much about it.

Now that the Mars mission study is done, and I will be off for a while with the knee, I can return to the question of ramjet-assisted launch. I’m pretty sure that horizontal takeoff with a two-stage vehicle is feasible with simple parallel-burn rocket and ramjet in a winged first stage. I’m pretty sure the staging velocity can be pushed to right at Mach 6 with a simple subsonic-combustion hydrocarbon-fueled ramjet. The upper stage rocket can be either winged or plain gravity-turn ballistic, as desired. To hit Mach 6 staging, a spike inlet will be required, which pushes practical takeover velocities to around Mach 1.5. Parallel-burn can be used right at staging to achieve path angle. I think the staging altitude is probably closer to 60,000 feet than 80,000 or 100,000 feet altitudes. That study needs a rerun with a resized engine and revised staging altitude. The earlier versions were posted here last year.

I don’t know yet whether ramjet assist is beneficial for a vertical-launch gravity-turn staged vehicle. But, if it is, it will be leaving the sensible, usable atmosphere closer to Mach 2 or 3 speeds than Mach 6. That’s a lower-speed ramjet design, most likely a simple normal-shock (pitot) inlet and a simple convergent-only nozzle. Takeover will likely be at slightly-subsonic to merely-transonic speeds. I have most of the guts of a sizing and performance code programmed, but it still does not quite work right in performance mode. Maybe I’ll have a chance to work on that while recuperating. Properly sized with an appropriate integral booster rocket, this kind of ramjet would be a strap-on staged off substantially earlier than the typical first stage burnout, in a two-stage vehicle. But it just might help.

Watch this space for future postings.

Saturday, May 7, 2011

Presentations Available for Lunch and Dinner Groups (v.8) GWJ 5-7-11

This is what I have available as of the current date. I would be happy to present any of these to any interested group. Just contact me.

Name: Ethanol Experiments (set 12 – final, 1-24-11) (15 slides)

Status: Ready

Summary: After characterization on gasoline during 2005, an old VW beetle was converted in October 2006, at no cost, to use E-85 ethanol fuel, and later tested as a “flex-fuel” on blends from E-15 to E-57 in 2010. An old farm tractor was also converted to E-85 with flex fuel potential. In 2007, tests began on blends from E-15 to E-45 in an unmodified pickup truck. Not long after, multiple pieces of unmodified 4-stroke lawn and garden equipment were operated routinely on E-22, then E-34 blends. In 2010, an unmodified 1998 Nissan Sentra was operated routinely on blends from E-20 to E-35, and once accidentally near E-50. Technical data of a very favorable nature were obtained on the truck and the VW. How-to information for do-it-yourself blend operations with unmodified vehicles is also included.

Name: Fuel Savings Advice (12 slides)

Status: Ready

Summary: This short presentation offers both technical truth and practical advice for anyone interested in saving fuel, independent of any switch to alternative fuels. The big items are matching vehicle to mission, and carpooling if possible. A smaller item is a national speed limit, but, surprisingly, 65 mph will do as much good as 55 mph. This is because of the tradeoff between road load reductions and efficiency losses as speeds decrease, an effect not considered when the old 55 mph limit was imposed in 1974.

Name: “One Book” Presentation (18 slides)

Status: Ready

Summary: This was prepared as a part of the Waco ‘One Book” project, spring 2009, related to the Homer Hickam book “Rocket Boys”. The presentation was to explain how and why I became interested in engineering, and what I did during my career, which included rocket and missile work. Many old aircraft, rocket, and other technical-item photographs were found and included, some quite rare. These were things that were simply “part of my life”, starting in the 50’s.

Name: Asteroid Results from Spain (26 slides)

Status: Ready

Summary: I presented a poster paper at the 1st IAA international conference on planetary defense, held April 27-30, 2009, in Granada, Spain. This conference dealt with detection of, and mitigation of, asteroids and comets that may impact the earth. Detection efforts are in progress, but incomplete, largely for lack of funding. Concepts for mitigation schemes were discussed, but with as-yet little real development work, again largely due to lack of funding. Civil defense coordination and warning mechanisms for this international problem do not yet exist. Not discussed at the meeting: propulsion to support such schemes does not yet exist, although I identified some promising ideas abandoned long ago. Some slides of pictures taken while touring Granada are included at the end.

Name: Global Warming (vers.B 14 slides, obs. Vers.A 13 slides)

Status: Ready

Summary: The earth’s climate is warming, as evidenced by polar sea ice thinning and glacier retreat on land. Icecaps on land could melt, causing massive sea level rise. Rainfall patterns (and agriculturally-fertile zones) could shift. Independent of “fault”, the options are to act, or not to act, in two areas. These are attempted mitigation, and coping with massive change. Concepts for mitigation are currently under public discussion and debate, but concepts for coping are not. The decision to act, or not, should be made on facts and logic, not politics and belief-preferences. Some experimental facts are given, and some recommendations made.

Name: Peak Oil and Coal (15 slides)

Status: Ready

Summary: The empirical “Hubbert curve” model for resource depletion is presented and explained. This includes its proper application and its limitations. Hubbert’s successful 1956 prediction with this model, of peak US oil production in 1970, is verified by historical US production data. The relative impact of Alaskan oil is included in the data. An opinion is presented regarding planetary “peak oil”, and its implications. Coal production in the UK followed a similarly-shaped curve, so the Hubbert curve model can probably be used for planetary “peak coal” predictions. An opinion is presented regarding that scenario, although the dates are less certain for coal.

Name: How Things Burn (27 slides, initial version)

Status: Ready

Summary: This presentation covers the “kitchen physics” and “kitchen chemistry” of how various gaseous, liquid, and solid fuels burn with air. The intended audience could be laypersons, or engineering students just getting started in this discipline. To the classic “fire triangle” is added (1) mixture limits and autoignition behavior, (2) how fuel phase changes interact with combustion, (3) three basic “burn rate” regimes, (4) the influence of theoretical thermochemistry predictions, (5) an explanation of how piston engines really work and their problems, (6) the “combustion aerodynamics” of several through-flow combustors, (7) how pool and pile fires really work, and the “firestorm”, (8) solid coal and carbon particles as the odd slow-burning case, (9) the radiation physics of fires, (10) simple models for real through-flow combustors, and (11) practical effects with gas-solid slurry fuels. (Emissions phenomena and some practical case studies will be added to the next version. Future versions will likely include rockets, and various kinds of explosives.)

Name: Ramjet-Assisted Staged-Rocket Launch Vehicle (20 slides v.11-18-09)

Status: Ready

Summary: This documents the results of a back-of-the-envelope three-stage vehicle sizing study that trades higher blended performance for the higher structural fractions that allow true re-usability. Subsonic combustion ramjets with integral boosters are added to the second stage, and burned during both first and second stage operation to improve performance substantially. The third stage is a plain rocket. This is the kind of design that could result from a “clean sheet of paper” start, looking at technologies not currently “traditional” for space launch.

Name: “Lob-Up” Nuke Launch (18 slides 11-30-09)

Status: Ready

Summary: This documents the results of a back-of-the-envelope two-stage vehicle sizing study that explores how to safely use nuclear thermal rocketry for surface launch. The design takes advantage of the ramjet-assist results to trade high performance for reusable structure in the lower stage, which lofts the upper stage and payload vertically out of the atmosphere. The nuclear upper stage then fires horizontally from its inertial apogee to reach orbital velocity with the payload. It never returns to earth, and its exhaust plume never enters the atmosphere.

Name: Carrier Plane Launch (19 slides 12-18-09)

Status: Ready

Summary: This documents the results of a back-of-the-envelope vehicle sizing study that uses a horizontal takeoff and landing hypersonic airplane as the first stage of a three-stage launch vehicle to orbit. The carrier aircraft is a scale-up and extension of the technologies in the SR-71, and the design staging point is M6 at 100,000 ft altitude. The upper two stages are simplified LH2-LOX rockets, arranged in a triple cluster for easy carriage under the airplane. These stages feature heat shields, pivoting wings, and small turbojets for flyback as 3 separate items. Final circularization and de-orbit of the 3rd stage is with storable hypergolic propellants.

Name: Oil Prices, Recessions, and the War (18 slides 2-5-11)

Status: Ready

Summary: Using gasoline price history data, this document explores the connection between fuel prices and middle east foreign policy issues, and between fuel prices and economic events. Both monopoly cartel pricing effects and supply-demand market effects are explored, including the possible effects of planetary “peak oil” just beginning to crop up. The feasibility and effects are explored of displacing (with domestic alternatives) about one third of the petroleum used for all liquid transportation fuels. (This presentation replaces “The Dark Side of Oil” as an expanded update.)

Name: The Mars Mission Design (30 slides 5-7-11)

Status: Ready

Summary: This mission and vehicle concept design study explores what could be done if one presumes a “clean sheet of paper” approach. Existing or very near-term technologies and hardware are “fair game”, but no restrictions to “legacy” concepts or hardware, or to existing contractor infrastructure, are imposed. The most startling result is that a super-heavy-lift launch rocket is not necessary to send men to Mars, at substantially less risk than was accepted for the Apollo moon missions. The second most startling result is that the direct launch costs can be quite “low”, compared to Apollo or the Shuttle. This is with no technology or hardware “breakthroughs” assumed for launch. It does assume carrying through with two of three nuclear propulsion technologies from 1959-1973 times.

Contact: Gary W. Johnson, PE, PhD
gwj5886@gmail.com
http://www.txideafarm.com
http://exrocketman.blogspot.com

AAAS Confirms 3 Topics

The American Association for the Advancement of Science (AAAS) publishes a refereed journal called “Science”, in which new findings are publicized, duplicated, debated, and verified. Issue 6024 of volume 331, dated 25 March 2011, has some very interesting items. The 1 April 2011 issue (volume 332, issue 6025) has more confirmation of my articles, and more details than anything I have seen (so far) in the public media about the nuclear disaster in Japan.

Relative to “Oil Prices, Recessions, and the War” dated 4 February 2011:

In issue 6024 on page 1510 is a “News Focus” article “Peak Oil Production May Already Be Here”. The “Science” article has a plot of actual production history data which verifies that non-OPEC oil production has already peaked. Closer inspection of the same plot reveals that OPEC oil production is peaking, or has just about peaked.

The article also makes the point that “unconventional oil” (such as the Alberta tar sands), cannot make up the difference between energy demand and a peaking conventional oil supply. These are all points I made in the “exrocketman” article.

It feels very nice to be verified by items published in a refereed scientific journal.

Relative to Pre-Clovis Hunters in Texas on “exrocketman” dated 9 April 2011:

In issue 6024 on page 1512 is a “News Focus” article about the Buttermilk Creek archeological site, in Texas. The actual technical report on those findings is on page 1599 of the same issue. The scientific debate and verification now begins, but it looks like they have made a pretty good case for people in Texas long before the Clovis hunters.

The institutions making up this team include Texas A&M, Baylor University, and the University of Minnesota. We can be very proud of these institutions (especially our two local ones).

It’s mighty nice to see “local folk” make good.

Relative to 3 articles on “exrocketman” about the Japan nuclear plant disaster:

In issue 6024 on pages 1504-1507 are three “News Focus” articles about the Japanese nuclear plant disaster and associated cleanup difficulties.

Issue 6025 on pages 24-25 has a News Analysis article that has more confirmation of my articles, and more details than anything I have seen (so far) in the public media.

These are also closely related to three articles of mine on “exrocketman”: “On the Nuclear Crisis in Japan 3-15-11, “Follow-Up on the Japan Nuclear Crisis” 3-17-11, and “Radiation and Humans” 3-24-11.

These “Science” articles confirm what I have been saying on “exrocketman”: that comparisons to the Chernobyl disaster are overblown. There is no credible risk in the US no matter what happens in Japan, or what tiny amounts of radiation might be detected over here. The risks in Japan are only serious within a few miles of the plant.

The Fukushima Daiichi plant has 6 reactor units, as has been widely reported. It has 7 spent fuel rod pools, one for each reactor unit, and 1 more for the entire plant, which has not been widely reported. None of these spent fuel rod pools had any sort of reactor-like containment, in spite of containing quantities of spent fuel rod assemblies resembling reactor cores. These pools were housed in buildings of ordinary construction that were destroyed by the tsunami, as was all the electrical and cooling water infrastructure for the entire plant.

According to this latest article, it is the spent fuel rod pool for unit 4 that seems to be the true problem, radiologically. The core meltdowns reported earlier seem to have little to do with the spread of radiation beyond the plant. Apparently, this pool went dry and its load of zirconium alloy fuel rod casings overheated and caught fire in the air. The article even mentions “aerosolization” of fuel materials and fission products from burning fuel rod assemblies, exactly as I wrote.

According to the articles, the long half-life and rather dangerous cesium-137 contamination found within a few miles of the plant has to be coming from the unit 4 spent fuel rod pool, because it has to come from older (spent) fuel. The very short (8-day) half-life iodine-131 contamination found as far away as Tokyo’s water supply is far less a threat, and cannot be coming from fuel rod pool 4. The article suggests reactor unit 3 as a possible source.

Finally, the article discusses upgraded design criteria for earthquake and tsunami risks, exactly as I advocated in my third article. This is the first time I have seen this issue raised in any public news forum. It is long overdue, of course. But, at least someone is beginning to look.

Once again, it is nice to be verified by data published in a refereed journal.

This may be a blog, but I always try to tell the truth. To the very best of my ability, I do!

Thursday, May 5, 2011

Ethanol Does Not Hurt Engines

A lot of folks seem to think ethanol will hurt their engine. This is not true. Here is how I know that:

The following is an excerpt from the “ethanol properties” downloadable document located on the ethanol projects sub-page on my website http://www.txideafarm.com. It addresses what materials can be used with ethanol and with “stiff” ethanol blends.

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“Materials compatibility is the next most important item. Ethanol is known to dissolve or damage certain materials, and can cause enhanced corrosion of metals, especially bare aluminums. You have to know what these pitfalls are, in order to avoid them.

Materials that cannot be used with ethanol but can be used with gasoline are old-time lacquered cork carburetor floats, the antique zinc-based “pot metal” castings for fuel pumps and carburetors, and Lexan or Plexiglas if there is warm vapor contact.

Materials that cannot be used with either gasoline or ethanol are natural rubber, butyl rubber, and polystyrene plastics. Both fuels dissolve these materials.

Materials that can be used with both fuels include neoprene rubber (any color), steel, aluminum, most polypropylene-type plastics, and both Lexan and Plexiglass if limited to liquid contact. Aluminum should be protected by a surface coating. Update 6-9-11: Teflon is also good with both fuels. Thus the typical aircraft fuel hose (stainless steel braid over teflon) is fine with ethanol.

The corrosivity of ethanol to aluminum and steel is not serious as long as the ethanol is dry, and it is far less than that of methanol, whose corrosivity gave both alcohols a bad reputation. The presence of 2+% water content greatly enhances ethanol’s corrosivity, however. The presence of water in the fuel can also cause phase separation problems (see below). Thus, if ethanol is used neat or in blend, it should be kept very dry.

As a rule of thumb, “anything good for gasoline is good for ethanol” is a pretty good guide, as long as Lexan or Plexiglas are not involved, and no truly antique parts are used (those are the zinc-based pot metal castings and the lacquered cork floats).”

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To this I would add the following about the “scare stories” being circulated by the small engine and boat motor lobbies. They quite often claim that gasohol fuels cause damage requiring engine overhaul. This is simply NOT TRUE. But there are two troubles to anticipate and avoid:

First: dirty fuel systems, which can be traced to really poor housekeeping on the part of the owner. The presence of ethanol in the fuel, with its solvent properties, will mobilize any pre-existing dirt in the fuel system, something gasoline will not do. This is quite the common problem with lawnmowers. That mobilized dirt will clog either a fuel filter or a carburetor jet, or both. You simply drain out and replace the dirty fuel (including that in the carburetor bowl), and clean or replace the clogged item. You DO NOT need to overhaul the engine.

Second: pre-existing water in the fuel system, something quite common in boats, and in lawnmowers kept outside in the weather. Ethanol in the fuel will scavenge water bottoms up to an unpredictable point (5-25% water by volume). Beyond that “limit”, the fuel will “phase separate” into a wet ethanol layer underneath a dry hydrocarbon layer. The engine is not carbureted to run on straight ethanol, and so will not run on the wet ethanol layer. Neither will it run successfully on the dry hydrocarbon fraction, which is devoid of any octane boosting ethanol or methanol added at the refinery. Simply drain and replace the fuel, including that in the carburetor bowl. You DO NOT need to overhaul the engine.

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If your fuel system is clean and dry, you may add any gasohol blend to an unmodified four-stroke engine as a “drop-in” fuel, up to about 35% ethanol, no modifications required at all. It will get the same fuel consumption it got on gasoline, it will run cleaner internally, its oil will stay clean longer, and so the engine will actually last longer. It will soot less out the exhaust, too, which means it is causing less pollution (US EPA’s oil lobby-induced fears notwithstanding).

I have been using E-22 to E-35 blends in unmodified cars and four-stroke lawn equipment for 5 years now (Brazil has been using E-22 since 1980). These vehicle and equipment items range from vintage 1960 to vintage 1998. I have been using straight E-85 in an old car (vintage 1973) and a really old farm tractor (vintage 1944) just as long. If there was a problem with ethanol, I would know about it by now.

There is no problem!

GW

Monday, May 2, 2011

The Good, the Bad, and the Ugly

Seems like good news and bad news always come together. Thus any conclusions must inherently be ugly. Oh, well, here it is.

The good news:

That was the most amazing and unexpected good news last night: Osama bin Laden is dead.

My congratulations to the US Navy Seals for a job well done, and to the intelligence community that made this possible. Keep up the good work! It's not over yet, there are at least two more top figures to go: Al Zwahari, and that other creep in Yemen. Plus all their followers, protectors, and imitators.

The spontaneous celebrations I saw on television in NYC and DC proved one thing: we are all still Americans. That's something that has been almost totally obscured by the vicious politics in recent years. (Congress, please take note, and start doing the people's business again, instead of playing those destructive politics-as-usual games.)

Putting an end to bin Laden is the result of a sustained effort spanning two presidential administrations. My thanks to both gentlemen, and all those who serve or served under them.

The bad news:

According to the released information, bin Laden was living in a gigantic compound just down the street from the Pakistani military academy. We didn't tell the Pakistanis we were doing this. There were no security leaks in this operation. I don't find those 3 items to be coincidence.

As near as I can tell, the Afghani and Pakistani Taliban are the same web of organizations. They protected Al Qaeda in Afghanistan, and I think they do in Pakistan, too. I believe the Pakistani Taliban not only controls large portions of Pakistan, they control a big portion of its government.

I'm hoping this upset will induce the non-Taliban Pakistanis to clean their house of Taliban and Al Qaeda, but I think that's a low probability outcome. The Taliban/Al Qaeda nuclear weapons will come from the Pakistani arsenal, I predict. The ties between the ISI (the Pakistani secret police and spy agency) and the Pakistani military on the one hand, and the Taliban/Al Qaeda groups on the other hand, are just too strong.

My conclusions:

The authorities are right to warn us to be vigilant, that the risk of a terrorist revenge attack is high.

Sooner or later, somewhere in the US or Europe, they will strike back as hard as they can.

Sooner or later, the “terrorist nuke” really is a credible threat.