High Altitude Wind Turbine Tower Design

@dougselsam
Doug:

You kick open doors.

Your explanations are as relevant as saying that air does not fall, or that water is wet.

You are in no way contradicting what others or I have said. I would like to point out again that the example of bottles or balloons releasing air was to help you understand, while you persisted in asking the question “why the piston” to which almost everyone answered several times.

In your endless tirades, you bring nothing other than your usual “know-nothing…”, projecting on others your own features.

:stuck_out_tongue:

Pierre: Like I said, you obviously have no grasp of the subject matter here. Sorry, but I studied a couple of semesters of fluid mechanics and fluid dynamics at a major university. What you think of as relevant treatment is typical layman’s noncomprehension of the most basic factors.

The difference between you and me in wind energy is that you, like that guy from the old forum, lighted LEDs to prove some minimal level of power output from your first prototypes using model airplane propellers, whereas I, expecting to make significant power from my model airplane propellers, used four (4) car headlights.

The reason you both chose LEDs is it takes almost zero volts and zero current to light an LED, creating the illusion of power where there may be almost no significant power actually being generated. LEDs are the choice when you don’t expect enough power to light anything more - a wise choice for most people.

I brought my early prototype using model airplane propellers out to a windfarm in Palm Springs, and was getting ready to set it up and see if it could light my headlight bulbs, when a utility truck drove up. I thought maybe I was about to get kicked out of the windfarm, but the guy was friendly and said he didn’t mind me being there. He also said the wind speed at hub height had reached 70 MPH. A few minutes later, when I let the prototype spin, it spun up so fast it instantly blew out all four (4) headlights in a blinding blue flash, making a popping noise that rang like a bell in the now-blackened glass enclosures. I had to throw it away from me to keep from getting sliced to bits! I knew I was on my way to making some significant power!

There were several reasons early on that I described the entire field of AWE as populated by “idiots, idiots, idiots”.

One was the way everyone talked about how easy it would be to eclipse existing turbines in the wind industry, when none of them had probably ever designed, built, installed, or operated even a single tiny turbine. So the first indicator was how easy they thought it would be, even though most of them knew nothing of the subject matter.

Then there was the idea that with all that combined supposed mental power, they should be able to use standard engineering calculations to predict how successful they should expect to be, but that didn’t happen either.

In my mind, I never included you in that “idiot” category, since you usually seemed to at least make sense, in general.

Today I am of the opinion that you might want to stick with something you know, something in which you are educated and have expertise, like music. You are way over your head in this discussion, and I wish you would stop now, before you do make a complete fool of yourself.

If anyone ELSE has a meaningful reply to my proposal that the moveable piston is without merit, and maybe has a response to the “thought experiment” I outlined, where we could insert and remove bolts attaching the piston to the cylinder without changing the dominant forces, I would be very much appreciative of an actual response.

Guy cables are problematic: they are ugly, take up space…

A normal tower by definition is close to the state of the art, so current towers could perhaps be used.

As a suggestion (see numerous comments from several writers questioning its usefulness), we also remove the piston.

It remains to be seen whether with compressed air the tower could reach higher altitude while supporting a heavy load, and according to what level of compression in regard to the diameter and the height. And also would the presence of compressed air require significant complementary construction for a classic tubular tower?

1 Like

Now the compressed air in the tower could be used differently, as a storage means. But in this case, the combination of a hypothetically greater resistance to reach a higher height and storage would be possible but within some limits.

The idea of ​​storing compressed air in the tower is not new.

Conventional CAES schemes are based on air at very high pressures of 170 bar or more, but in wind turbine applications such pressures are impractical and not necessary.

A storage pressure of as little as 10 bar can provide enough stored energy for a practical system. Such a low pressure should be accommodated with little modification of the turbine buoyancy chamber, which has to be of significant wall thickness to cope with normal transport and operating stresses.

In its simplest form, a CAES system for an offshore wind turbine would use a multistage compressor driven from the electrical output of the turbine generator, and a separate expander-driven generator, to feed back the stored energy when there is sufficient demand.

This information could also be useful if the option of a more rigid and taller tower by using compressed air is favored.

See also pneumatic telescopic masts, possibly for wind turbines, and working at low pressure (1.4-2.4 bar).

http://www.german-electric.net/download/mobilemasts/willburt/Pneumatics.pdf

https://totalmastsolutions.com/mast-applications/anemometer-towers-wind-turbines-met-masts/

It’s a neat beginning of an idea.

I’d do a better comparison of the relevant alternatives, of which there are multiple. You’re only doing some off-the-cuff calculations in the linked video. You can also explore the drawbacks mentioned here.

Offshore, where installation and maintenance costs are very high for each tower anyway, it does make sense to make each turbine bigger. Onshore I still think it does, but perhaps less so, and even less so if you install just the single tower, which you would be doing at first, and would be just a research project anyway.

Where can you buy 4 dollars per kilogram dyneema rope?

Searching for “lightweight construction” on Library Genesis gave the book “Optimal Lightweight Construction Principles” for example, in which chapter 7 for example should help “Bending of Lightweight Inflated Circular Tubes—Optimal Design”.

The guying and the compressed air tubular tower could be the subject of specific studies, one not directly dependent on the other.

It would be necessary to see and calculate to what extent compressed air makes it possible to lighten the mass of the tower (if this is really the case) and to allow heights of 2 to 3 times the current tower heights, i.e. approximately 300 m.

Very high pressure is not necessary. We can therefore imagine a 300 m tubular tower in proportions similar to or narrower than those of current tubular towers. A pressure of 5 bars or less might be enough. The excess pressure could also serve as storage. But all this requires calculations.

A link to different types of tour:

Tubular steel towers are the most widely used solution. They normally have a conical shape and a diameter varying from approximately 4.5 meters at the base to 2 meters at the top, divided in 3 or 4 sections assembled at the wind farm (they are bolted together). The length of a section can vary from 20 to 30 meters. Basically they are manufactured with steel sheets cut, rolled and welded.

A post was merged into an existing topic: Slow Chat II