of waters and winds

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dunno
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Re: of waters and winds

Post by dunno » 2021 Mar 10, 03:43

nikos wrote:
2021 Mar 09, 06:38
dunno sometimes you're more verbose than kilmatead :)
can you, in under 10 words, tell us if my main article thesis is right or wrong, according to your fluid dynamics excellence? :)
Cold air will have a slight increase in performance over hot air, for your sail purposes its irrelevant.
Concise enough :-))

Measuring wind speed, It all starts with Kinetic energy = 1/2mv² and apply the principles of Impulse turbine.
https://learnmechanical.com/difference- ... n-turbine/

Atmospheric air is not in a sealed container so sometimes its reaction to external energy is counter intuitive, for instance, in a sealed container if heat is added to the contents the pressure will increase, not so in a container-less environment.

Wind flowing down along a valley is a classic example of Bernoulli's theorem relating to static and dynamic pressures. Houses explode during tornadoes and hurricanes due to steep pressure gradients, very low pressures behind the structure (leeward side) created by aerodynamic forces literally pulls the structure apart, a structure can be designed to withstand the (windward) Kinetic energy the problem is the intense Low pressure created behind the structure, if there's no means of equalising the pressure differential along with weak structural strength, boom a major suck job.

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nikos
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Re: of waters and winds

Post by nikos » 2021 Mar 10, 06:07

this is Sparta!

dunno
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Re: of waters and winds

Post by dunno » 2021 Mar 10, 06:50

nikos wrote:
2021 Mar 10, 06:07
this is Sparta!
Whilst we're on good terms, I'd like to ask you a sailing question.

Do you think it would be easier to tack dual panes if there were drive icons above each pane, seems logical that the quickest way to change direction in a pane is to go directly to the drive bar above it instead of navigating all the way to the other side to change direction. currently its kind of like a windsurfer with only half a boom, has to do everything from one side, not very efficient and intuitive.

I hope I haven't ruined the friendship :D

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Re: of waters and winds

Post by nikos » 2021 Mar 10, 07:42

one day we will have "2 of everything" (trees, drivebars etc)

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johngalt
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Re: of waters and winds

Post by johngalt » 2021 Mar 10, 15:42

[TAB] is a great way to switch panes. But I'm (mostly) a keyboard junkie anyway.
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Re: of waters and winds

Post by dunno » 2021 Mar 11, 03:28

nikos wrote:
2021 Mar 10, 07:42
one day we will have "2 of everything" (trees, drivebars etc)
for two trees, I would suggest calling this option "Tarzan" Mode.

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Re: of waters and winds

Post by johngalt » 2021 Mar 11, 04:00

And now I can't get his 'call' out of my head.

Sigh.

BTW - my apologies for trying to steal your thunder - I honestly read Nikos' reply to you as if it were written to me.

I'm a dunce sometimes, is all.
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Re: of waters and winds

Post by nikos » 2021 Mar 12, 19:46

double trouble
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Re: of waters and winds

Post by johngalt » 2021 Mar 12, 20:49

I see the word image there - but no actual image. Might be on my end - I'll try in other browsers to see if it works...
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Re: of waters and winds

Post by otlaolap » 2021 Mar 13, 00:33

nikos wrote:
2021 Mar 10, 07:42
one day we will have "2 of everything" (trees, drivebars etc)
Four would be truly nice . . . . Four panes; I'd go with one drivebar and one menubar and no trees. Love the way the wind blew this thread!

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Re: of waters and winds

Post by dunno » 2021 Mar 13, 04:01

@ Nikos
Yep that ought to do it, now the boom is complete and the surfer can tack efficiently from both sides, irrespective of whether there's a cold or hot breeze.

it's all about being able to visualise air, during my observation of a few hang glider competitions I noticed that some very competitive Hang glider pilots would set fire to brush or fields in order to assist with the visualisation of air currents, I dissaproved of this and ceased attending these meets.

A synoptic chart will give one a good indication of prevailing winds on a macro scale but on the micro scale i.e. local scale topography plays a very important factor in determining wind/air behaviour. In the southern hemisphere wind rotates anti-clockwise around a high pressure and clockwise around a low pressure. Its opposite in the northern hemisphere. Or just phone your local Aviation Meteorological office and ask them for the low level winds in your area. If there's a Airport in the vicinity read the METAR for the current weather at the airport and the TAF for forecast, there are several sites which will decode the jargon/abbreviations for you.
All runways are aligned with the prevailing winds of the region/area, runways are designated by numbers which depict the magnetic heading of the runway, i.e. 27 = 270 degrees. 01 = 010 degrees.; 09 = 090 degrees etc.

I haven't visited maritime weather/meteorological sites but I'm certain that they will have all pertenant data as well.

Anyway i'm rambling here and my apologies if I'm preaching to the choir.

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