Plasma drag reduction

[freebeard]

First time I've clicked on a Google link in a long, long time; they changed their format.

Probably Helium, but it could be steam.
www.researchgate.net: Advances in Steam Aerostation

Such an airship filled with steam lift gas could of course be powered by a conventional gasoline or dieselaeronautical engine, but the intriguing possibility arises of using a steam engine. The spent exhaust steam from the engine would naturally be discharged into the envelope to replenish the lift gas. Since a steam airship must in any case carry a boiler for reboiling the condensate water, and since the envelope itself would function as the condenser for the steam engine, only the actual steam engine itself would be required in addition. A steam reciprocating engine can be quite lightweight and is very reliable, and its high torque and low rpm characteristics are very suitable forairship application. Moreover, maneuvering thrusters could be driven by steam vane motors, which are very light indeed, so they could be mounted at any convenient point on the envelope. (ed: Else plasma actuators, obv.)
....
Any possible actual development of a steam airship is a long way off, but the general outlines of what might be possible are emerging. Within limits, the picture is encouraging. First, the obvious disadvantages of using steam lift gas in an airship are relatively low lift, and the necessity for reboiling the condensate water. The advantages are cheapness, and the ability to deflate the airship after each flight, thus obviating the need for a hangar or mast. A rigid airframe would sacrifice this second great advantage of steam lift gas while preserving all its disadvantages, and so I think that the idea of a rigid steam airship is a non-starter.

So why not a semi-rigid? The Plimp:

Egan Airships: The PLIMP™ Invention
But compare the maneuverability of the Roboloon:

Airship Drone | Waypoint Flight-Test

At 1:06 watch it cut the propeller half way and coast to it's destination.

[Logic]

Originally Posted by freebeard

First time I've clicked on a Google link in a long, long time; they changed their format.

Oops: I fixed the link to go to:
https://www.newscientist.com/article...ound-to-space/

Originally Posted by freebeard

Probably Helium, but it could be steam.
www.researchgate.net: Advances in Steam Aerostation

Completely Off Topic but whatTH!

I have never even considered steam as a lifting gas!
Thx. That opens up a hole new rabbit hole!

IMHO Hydrogen is THE lifting gas.
Did you know the helium lobbyists added oxygen to their 'dangerous hydrogen' demo blimp before blowing politicians of their grandstand with it!?

NB: I'm not saying a manned, passenger carrying blimp should be filled with H2.
I see no future for blimps as passenger or even cargo carriers anyway:
It doesn't matter how safe you make them or how clever you are about not popping up like a cork when you offload your cargo; you are still at the mercy of the wind as to what direction you can travel in.
ie: With all that surface area for the wind to catch, their economical airspeeds are barely faster than a light breeze. So unless where you want to go happens to be downwind of where you are...

All the filmed demo flights share the same 'Not a breath of wind' one sees in 2 wheeled velomobile videos.

Originally Posted by freebeard

So why not a semi-rigid? The Plimp:

Egan Airships: The PLIMP™ Invention
But compare the maneuverability of the Roboloon:

At 1:06 watch it cut the propeller half way and coast to it's destination.

My interest is in ...erm... kites that don't drop to the ground when the wind stops blowing.
ie; The pictured method of semi rigid blimp construction, on a 'string'.


So when windless; it just bobs about like a party balloon on a string, but when the wind does blow you want the wind to impart lift so your 'party balloon on a sting' is not blown down to the ground.

[Logic]

SO what happened to THIS post??

Originally Posted by teoman View Post
I am gearing up to give this a go.

I have copper tape and kapton tape to create the plasma generators and as a power supply i have the module from a tazer and the electronics of ozone generators (they create plasma which creates ozone)

Would adding these generators to the wheel wells be beneficial?

And what is an initial good design for the rear of the car?

@ teoman:
aerohead is just fine with plain old tuft testing and mpg comparisons when boat tails etc that add weight are discussed.
Yet somehow DIY DBD requires a supercomputer..?

Tuft Testing:

https://ecomodder.com/forum/showthre...ing-38611.html

NB that around 98% of driving worldwide is city, stop-go driving where overcoming inertia (weight) uses up 68% of your fuel and aero drag only uses up 14%
https://ecomodder.com/forum/showthre...ban-41665.html

So a pattern is emerging in which it is obvious that modifications that consume more fuel than they save, on average, get a 'Ra-Ra! You go boy!' pat on the back from him, while things that might actually help get dumped on from a dizzying height, using 'big words' and phrasing that sounds far too technical and daunting to ever understand.

Someone who truly understands a subject, inherently has the ability to explain it to interested lay people in a way they will understand.
Doing the opposite is a sure sign that the person is simply trying to discourage you and, in all likelihood, has no idea whatTF the technical jargon they have spewed out actually means, if it means anything at all!
No links proving and explaining the often incomprehensible technical jargon are ever given.
That's another sign.

Also boat tails tend to 'steer' cars in crosswinds making for instability.
Then, as well made as it is, imagine driving this around town and parking it!

https://ecomodder.com/forum/showthre...tml#post183164

In short: pay no attention to obvious troll like behavior and certainly don't ever be intimidated into deleting your posts!
(Normally I, like most here, wouldn't even bother reading his posts, but in this case he is 'Big Scary Boogymaning' you, who actually wants to try DBD and see for YOURSELF..!


To answer your questions: (in easy to understand, logical, layman's terms)
Basically with tuft testing a tuft that is staying downwind and relatively still indicates smooth, attached, low drag, laminar airfflow.
When the tuft is flapping about, every which way, like crazy; flow is unattached and turbulent and high drag.

So anywhere tuft testing shows a change from laminar to turbulent flow is a good place to put your DIY DBD.
Then further tuft testing around and after it would indicate if it worked or not, with old fashioned mpg testing as the last word.

Generally around the rear of the car, where it's 'shrinking' in size is where tufts start going crazy and is where DBD should help.

https://ecomodder.com/forum/showthre...tml#post696530

It might take some minor moving about of your DIY DBD to find the best place.
That's all part of the fun!

Voltages:
NB that the voltages you want are down in the low amp ionic breeze regime. Not up where a high amperage, welding type spark occurs.

If electricity was water in a hose; voltage would be the water pressure and amperage would be the water flow.
Power required is pressure multiplied by flow or P (in Watts) = Volts x Amps
You want high pressure (volts) and low flow (amps) so you that you don't need a lot of electrical power for your DBD.


Here's a graph that summarizes things:


You are looking to be in the "Corona to Normal glow" area of the graph.
What voltage that is exactly is hard to say.
It will mostly depend on the characteristics of your dielectric (Kapton Tape), so a controller for the low input voltage side, into your tazer or ozone generator is required.

If you tell us what exactly you have, we will be able to advise you further.