Received: from opus.hpl.hp.com (opus-fddi.hpl.hp.com) by jr.hpl.hp.com with ESMTP (1.37.109.24/15.5+ECS 3.3+HPL1.1) id AA065412128; Tue, 27 Oct 1998 15:49:05 -0800 Return-Path: <matt@cup.hp.com-DeleteThis> Received: from wallach.cup.hp.com by opus.hpl.hp.com with ESMTP (1.37.109.24/15.5+ECS 3.3+HPL1.1) id AA162902119; Tue, 27 Oct 1998 15:48:39 -0800 Received: from wallach.cup.hp.com (localhost [127.0.0.1]) by wallach.cup.hp.com with ESMTP (8.7.1/8.7.3 TIS Messaging 5.0) id PAA15010; Tue, 27 Oct 1998 15:33:42 -0800 (PST) Message-Id: <199810272333.PAA15010@wallach.cup.hp.com-DeleteThis> To: wind_talk@opus.hpl.hp.com-DeleteThis Cc: Paul Catz <paulcatz@unix.SRI.COM-DeleteThis>, David Ahlberg <ahlberg@mathcs.sjsu.edu-DeleteThis>, Kyle Welch <kwelch@us.ibm.com-DeleteThis>, The Goat Man <Feferman@Haas.Berkeley.Edu-DeleteThis>, Jon Berman <berman@cisco.com-DeleteThis> Subject: Re: FWD: Coyote Alert In-Reply-To: Your message of "Mon, 26 Oct 1998 13:56:22 PST." <199810262156.NAA12369@wallach.cup.hp.com-DeleteThis> Date: Tue, 27 Oct 1998 15:33:41 -0800 From: Matt Yamamoto <matt@cup.hp.com-DeleteThis>
I talked to a friend who once told me some information about how
big a wind shadow an object of a certain height throws up. Here's
his response:
Well, I went home and looked at "Sailing Theory
and Practice" by C A Marchaj, p. 387. It wasn't
the reference I remembered, but it gave
the wind shadow for trees as being anywhere
between 4 and 20 times the height - I assume
the variation is due to the wind speed, which
changes the Reynolds number.
So a wind shadow of up to 20 times the height of an 11 story
building could be significant. Doing the math:
11 stories * ~10 ft/story * 20 (times the height) = 2200 ft
or a wind shadow of about .42 miles. Even a 7 story building could
throw up a wind shadow over 1/4 mile long.
-matt
> Date: Fri, 23 Oct 1998 13:02:37 -0700
> From: Rick Weiss <rickw@nablewest.com-DeleteThis>
> To: wind_talk@opus.hpl.hp.com-DeleteThis
> Subject: Re: Coyote Alert
> Message-ID: <3630E0DD.435C@nablewest.com-DeleteThis>
>
> Martin Frankel wrote:
> [snip]
> > This is all speculation, I don't really know the first thing about the
> > physics involved. If anyone has better knowledge of this or perhaps
> > references, I think it would be very interesting. Still, the first
> > priority is to get the issue on the table... send those letters!
>
> I'm confused. We cannot decide whether these buildings would REALLY
> affect our launch, but we should fax those letters, which say they
> would "severely impact, and possibly destroy" our launch. I agree
> this could be a significant problem, but I'd hate to cry wolf.
>
> (I'm trying to picture standing in the parking lot, and mentally
> place the proposed buildings. They don't seem to be directly upwind.
> Does anyone have a map, where they could plot the proposed buildings,
> and draw a line at 260 degrees --- the point where it starts to become
> too southwest-- to see where that hits Coyote point?)
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