Diesel costs about $1/litre. That is $1 for 10kWh of stored energy. If electricity can be sourced at $0.1/kWh, then hydrogen should approach cost competitiveness with diesel.
]]>A 300-350 bar compressor is reasonably small, light, affordable, and typically water-cooled to get rid of waste heat (heat we want to store for later use in the car). Perhaps $500 to $1,000. Some individuals own these if they do a lot of diving or paintball or air rifle practice. A 700 bar compressor is not small, light, or affordable, at least several thousand dollars, but more like $5K to $10K for a machine that can get the job done in a reasonable amount of time. A gasoline pump at a gas station costs a lot more than that, so it's a machine that a gas station can pay for by charging customers to refill their car.
I don't see the point to owning potentially very dangerous charging equipment at home, whether it's a high power battery charger or 700 bar air / H2 compressor. Knowing how to charge or refuel a car is one thing. Knowing how to service the charging or fueling equipment is different. Yes, some people do it. It's not something I want my wife or children messing with. As I said before, it belongs at a gas station / service station / servo.
You're looking at 35kg to 55kg for a good 300 to 350 bar unit, commonly used by SCUBA and paintball shops. I don't know about a 700 bar unit, but I know it's not going in a car. 700 bar paintball and air rifle units are not at all suitable for filling 360L of tank volume with 700 bar compressed air, because they're not intended for extended duration / continuous duty use. Most of those recreational compressors have a 30 to 45 minute operating time cutoff.
45L 300 bar steel compressed air cylinders weigh 65kg to 75kg each. The industrial compressed air tanks I looked at were about 68kg each, less fittings and hardware, so 544kg for 8 tanks. It's a two man lift, and you need to be reasonably strong to do it. It has the benefit of being cheap, because it's steel. Let's call it $1,200 worth of steel.
I would skip Aluminum tanks entirely, even though they're a good "in-between" CFRP and steel. Salt water dive shops near the equator use Aluminum instead of steel because scratched or unprotected steel corrodes way too fast. They won't pay to shot blast and repaint the steel tanks, so they get scratched being dragged back into the boat or along concrete piers, but mostly accumulate water vapor inside during filling, so then they rust, and then they're junk in a year or two. The inside rust is way more problematic than the outside, though. Someone could invent a machine to shot blast inside the tank and that would solve the rust problem. Aluminum has a strict service life limit, but is essentially zero maintenance, which is why dive shops like them. Aluminum is also very easy to recycle. Someone else can make the case for Aluminum, but I view the most realistic options as CFRP (maximum performance) or hot-dipped galvanized steel (maximum economy to the consumer for very short-range vehicles).
Type IV (high modulus fiber with a HDPE liner) 700 bar / 10,000psi CFRP is less than half as heavy as 350 bar steel, about a quarter the weight of steel in an optimal configuration. As the images below indicate, this is why you really want Hydrogen or Methane or Propane, rather than Lithium-ion batteries or compressed air and hot water.
360L of volume for 350 bar steel is 544kg.
360L of volume with 700 bar Type IV CFRP / HDPE is 143kg in a mass-inefficient configuration, so 3.79X lighter.
360L of volume with 700 bar CNT would be about 75kg or less, same mass-inefficient configuration (using a bunch of little tanks).
CNT tanks buy 160Wh/kg.
What does 160Wh/kg represent?
A 100kWh Tesla Lithium-ion battery pack weighs 625kg, so 160Wh/kg.
CNT 700 bar compressed air tanks achieve Tesla battery pack performance without a battery. CNT fiber doesn't have a functional service life limit. The plastic liner and resin will eventually degrade, but the fiber will not. NASA gave up on breaking the fiber after bending it back and forth over 1,000,000 times. At the point at which we achieve Lithium-ion battery pack level performance without any Lithium-ion batteries, nor power-robbing performance degradation, we have to question the reason to use Lithium-ion or Sodium-ion batteries for vehicle applications, because it won't make any economic or environmental sense.
]]>5 Wildly Futuristic Concept Cars of the 1950s
https://www.autoevolution.com/news/5-wi … 29798.html
Developed in 1958, the concept looked like a blend between a pickup truck and a speed boat, yet its appearance wasn't the wildest thing about it.
As the name implies, Ford wanted to power the vehicle with a small nuclear reactor. Yes, you read that right, a scaled-down nuclear reactor inspired by those who went on to power military submarines.
recently in news, subscribe paywall
Nuclear spaceflight: igniting the next era of exploration
https://physicsworld.com/a/nuclear-spac … ploration/
If we want to send humans to Mars, and launch more science missions to the outer solar system, then we need the firepower to get there. One technology that could usher in this new era is nuclear-propelled rockets. This video traces the history of the nuclear spaceflight concept and looks at two complementary approaches being developed today: nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP).
Xiaomi’s latest robot dog does backflips off skateboards, costs $3,000
https://uk.news.yahoo.com/xiaomi-latest … 54297.html
Tiny robotic crab is smallest-ever remote-controlled walking robot
https://news.northwestern.edu/stories/2 … ing-robot/
Smaller than a flea, robot can walk, bend, twist, turn and jump
Elon Musk welcomes competition from humanoid robot rivals: 'Bring it on'
https://www.yahoo.com/news/tech/elon-mu … 27403.html
For kbd512 re link below ...
Just FYI ... I tried the link today, and got a 404 ... perhaps the article is just moved?
(th)
captured in archive but no images
https://web.archive.org/web/20140929203 … ger-camel/
Impressive find! Thanks !!!
That would be quite a "tourist" flight, and a lot safer than the high altitude idea.
There might be a reason to question how "safe" a flight across the polar ice cap might be, but I'll bet passengers have to sign risk release statements before either flight.
(th)
]]>ARES was a proposal to build a robotic, rocket-powered airplane that would fly one mile above the surface, there was also proposed airplane mission concept to Titan and a soon to fly Dragonfly mission.
A continued debate on Planetary Ballooning, Airship etc
https://www.nasa.gov/scientificballoons … -balloons/
Since the success of the Helicopter some have considered a flying device that lifts and breathes and sucks air. The idea of an engine mixing with sand and dust seems a real danger, on our planet Earth Flying in a dust storm or heavy snow material or volcanic ash should be avoided.
Did a Volcanic Eruption Cause BA Flight 09’s Engines to Fail?
https://www.youtube.com/watch?v=_e4GwjVxrTs
Armenia Itinerary
https://wander-lush.org/ultimate-armenia-itinerary/
Montreal's Metro will be open all night for Nuit Blanche
https://montreal.ctvnews.ca/montreal-s- … -1.6784022
Riding the Rails in Argentina
https://www.railsouthamerica.com/blog-p … -argentina
Just how reliable is public transport in Norway?
https://www.thelocal.no/20240209/how-re … -in-norway
In bigger cities like Oslo and Bergen, the public transport systems, including trams, metro lines, and city buses, are well-integrated, making urban travel relatively straightforward and reliable
Hanoi's second metro line prepares for launch with French safety guide
https://e.vnexpress.net/news/news/traff … 17071.html
Meralco injects P280M to provide reliable power for Metro Manila subway project
https://mb.com.ph/2024/2/19/meralco-inj … ay-project
Outrage as Sydney train lines closed on Mardi Gras weekend: 'Unbelievable'
https://www.dailymail.co.uk/news/articl … vable.html
China is building a train that’s faster than a plane – but will it work?
https://www.independent.co.uk/tech/chin … 04794.html
Sweden, Stockholm, subway ride from Skanstull to Medborgarplatsen
https://www.youtube.com/watch?v=F_7ofhlxGKo
PM Modi Set To Inaugurate India's First Underwater Metro Tunnel In Kolkata
https://www.youtube.com/watch?v=6s_HwdD2s-g
interesting amphibian.
I asked Google when wind shield wipers were invented. For some reason, no one had imagined a way of cleaning wind shields until a wiper was imagined by a female visitor to New York.
With all due respect to Ford, GM and everybody else who was making cars in the early days, cleaning the windshield was pretty far down the list of priorities .... I think the same is (was) true for the first generation of robots to travel to Mars.
Windshield Wiper Invented In 1902 By A Woman Who Didn ...
NPR
https://www.npr.org › 2017/07/25 › alabama-woman-stu...
Jul 25, 2017 — Entrepreneur Mary Anderson thought it made no sense that New York streetcar drivers had to keep jumping off to clean snow from the ...
(th)
]]>I used that facility with permission while teaching an aircraft systems course. I brought the students out and had them operate the PT-6 and prop pitch as part of teaching how gas turbine engines worked. The idea was to make the dry classroom content "real" to students training to be future airline pilots, who would otherwise get most of their training flying piston aircraft. My students all told me (and others), that that class was the very best one they had, at Baylor.
Experimentally, I tested biodiesel blends with Jet-A in that PT-6. I would diagnose combustion problems by stepping into the blast and sniffing the odors. I could tell the source of the biodiesel: converted grease from the fast food places smelled like French fries cooking, and converted tallow from the slaughterhouse smelled like barbecue cooking. Any time the burner cans were not fully efficient, you could smell kerosene in the stream.
It turns out that the biodiesel in the blend actually rejuvenates old fuel bladders that are getting stiff. That was a pleasant surprise to me and the FAA. That result was a part of how I was able to put a Beech King Air into "experimental" for flight tests of the experimental fuels, and still bring it back to "standard", all in 6 months. The other part was exposing only one engine, and doing a hot section overhaul on that exposed engine before going back to "standard".
This was all 1998-vintage stuff, long before the current "sustainable" fuels.
GW
]]>Modified "Hot" Beta engine
https://www.stirlingengineforum.com/vie … php?t=5598
Stirling engines using working fluids with strong real gas effects
https://www.sciencedirect.com/science/a … 1110001390
Specific Output - Stirling Engines
https://www.beyonddiscovery.org/stirlin … utput.html
The size and weight of Stirling engines for a given power output is important in many applications, particularly in the automotive, locomotive, space, and under-watcr power fields. It is still important, bul rather less critical in the stationary generator, heal pump and total energy, and surface marine fields.
For the First Time Ever, China Tested a Stirling Engine in Space
https://www.popularmechanics.com/space/ … ter-china/
The converter could provide a viable source of energy for future space colonies.
SLIM compared with
https://twitter.com/nvslive/status/1739270189416603805
Googlemap