On Sun, 14 Mar 2021 11:28:35 +0000, Keith Willshaw
>On 14/03/2021 05:19, Barrk wrote:
>> It won't be produced economically. Just more Star Trek
>> bullshit. Kerosene and compressed air - it will be THE
>> best way, by far, for decades. Add up the costs of
>> losing cheap air transport and then suck it up and stick
>> with the status quo.
>Plasma and Ion Drives work well in space because of their high specific
>thrust and low mass requirements but they dont work worth a damn in
>atmosphere. The electrical power required is high and they dont make
>extension leads that long :) The proponents have suggested using
>microwave transmission, lots of luck with that on a rainy day. It doesnt
>do much good to human beings either.
Ever seen a "plasma cutter" ? It's a great alternative to the
old oxyacetylene torch. There are two tungsten electrodes,
a pin inside a ring. Push the button and a high-amperage
arc starts between the electrodes and you blow air through
the gap. The result is a blue-white "flame" an inch or so
long at about 8000 degrees which is mostly "plasma"
that's 20% atomic oxygen. Cuts thick plates of steel like
That sounds a lot like what this proposed engine is. An
arc superheats air which is then expelled either like a
rocket or tapped to turn a turbine blade (more efficient).
PROBLEM is the AMOUNT of power required to create
that plasma. It's HUGE. Even a smallish plasma cutter
has to be plugged into 220v with a 50 or 60 amp-rated
feed. 60amps x 220v = 13.2 kilowatts, about 17 horsepower.
Your house maybe uses that much if the A/C and water-heater
are on at the same time.
And sorry, that itty bitty flame isn't going to make much
of anything fly. You'd do better using the KWs to heat water
to run a steam turbine.
>For short and medium ranges High Speed rail is definitely useful. The
>introduction of the 185 mph TGV trains in Europe pretty much decimated
>the domestic aviation market and probably coould do well on the US East
>Coast. In the UK HS2 is being built and that will provide the
>infrastructure for trains that can run at 250 mph but its worth
>remembering that HS2 will have stations at Birmingam and Manchester
Rail has its place, and it doesn't have to be "high speed".
But, rails use up real-estate and need a lot of service and
only take you to a rather narrow line of destinations. Air
is more versatile. CO2 saved via rail shows up again as
you try to get from the train station to your real destination
30+ miles away. IF you have enough PV cells and windmills
then clean electrics would get you to the final destination,
but those things are not free and a lot of CO2 and other
pollutants are involved in the manufacture. The batteries
are a real disaster too.
>Medium aand long haul aircraft will still use turbofan engines but one
>option being seriously looked at is using LNG fuel, if nothing else its
>cheaper than kerosene.
Airliners blow up easily enough with kerosene, pressurized LNG
would be a lot less safe. Oh, and "pressurized" means you have
to have fuel tanks built strong enough to hold the pressure. That
means a lot more weight.