Ridge lift calculation

David Williamson

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Jan 13, 2002, 1:11:47 AM1/13/02

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Can anybody give me a formula that can (roughly!) calculate ridge lift based
on ridge slope angle , wind speed and direction and distance from the ridge.

dj...@ihug.com.au

Mark Navarre

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Jan 13, 2002, 2:26:10 AM1/13/02

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>Can anybody give me a formula that can (roughly!) calculate ridge lift based
>on ridge slope angle , wind speed and direction and distance from the ridge.

No formula, but on pages 163 and 165 of the Dennis Pagen book "Understanding
The Sky" you will find excellent charts describing the info you seek.
Send me your email and I will scan the pages and send as a jpeg.

Mark Navarre

-

DGRTEK

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Jan 13, 2002, 8:35:45 AM1/13/02

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Mark,
While your sending that to David, would you be kind enough to forward that to
me as well? DGR...@AOL.COM, TIA
Douglas
PS Ridge is about the only lift in my neck of the woods right now.

cterlecki

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Jan 13, 2002, 10:52:15 AM1/13/02

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A note for those who have not had a chance to gleam this gem of a book---its
outstanding and worth every penny. Every page has some little pearl to tuck
away in your noggin.
"DGRTEK" <dgr...@aol.com> wrote in message
news:20020113083545...@mb-fc.aol.com...

Tomasz Sielicki

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Jan 14, 2002, 11:22:29 AM1/14/02

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Ridge surface: whether plain rock or forest, for example, will make a difference
as well, I guess - at least when close to the ridge ... ?

Tomasz

Rod Pool

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Jan 14, 2002, 7:21:09 PM1/14/02

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Gentleman
This book is outstanding.
D. Pagan deserves to be rewarded for his work. Buy the book. To do otherwise
is wrong and illegal.

Regards

Rod
"cterlecki" <cter...@atbi.com> wrote in message
news:P2i08.12999$Tq.81186@rwcrnsc54...

DGRTEK

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Jan 14, 2002, 8:40:10 PM1/14/02

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You're right. I'll be placing my order on amazon tonight. Took a minute to
find it. Just do a search on understanding the sky. Thanks for the reminder!
Douglas

Frank Dobbs

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Jan 19, 2002, 5:46:21 AM1/19/02

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Tomasz Sielicki <tsie...@tchr.org> wrote in message news:<3C4305C5...@tchr.org>...

The other thing to remember is wave effects from other high ground
upwind. This can be very disconcerting, as wave wavelength can alter
suddenly, resulting in sudden disappearance (or appearance) of ridge
lift without any appreciable change in wind strength or direction.

Frank Dobbs

Fly Dartmoor Wave
Devon, UK

Eric Greenwell

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Jan 19, 2002, 10:46:35 PM1/19/02

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In article <ffef8e3f.02011...@posting.google.com>,
fdo...@totalise.co.uk says...

> > > Can anybody give me a formula that can (roughly!) calculate ridge lift based
> > > on ridge slope angle , wind speed and direction and distance from the ridge.
> > >
> > > dj...@ihug.com.au
>
> The other thing to remember is wave effects from other high ground
> upwind. This can be very disconcerting, as wave wavelength can alter
> suddenly, resulting in sudden disappearance (or appearance) of ridge
> lift without any appreciable change in wind strength or direction.

What would be the purpose of this calculation? Surely, experience
would quickly tell you the conditions required to stay up. As Frank
points out, any formula would be rough indeed, if wave effects are
there. Also, the wind gradient can make a huge difference, for
example:

-strong winds on the hill top (but not strong lower on the hill) may
not produce good lift, and may actually produce sink below the strong
layer

-strong winds on the surface may not flow over the hill, but around it
instead

Another factor is the shape of the ridge, because gullies and small
ridges can channel a wind that impinges even far off perpendicular.
--
Delete the REMOVE from my e-mail address to reply directly

Eric Greenwell
Richland, WA (USA)