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Fw: [wind_haz_mit] Re: Fw: Wind Tunnel Testing

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I forwarded the original enquiry to the wind_haz_mit egroup. Here is a reply
which may interest you.

James Cohen

-----Original Message-----
From: Zysko-1, Jan <Jan.Zysko-1(--nospam--at)>
To: 'wind_haz_mit(--nospam--at)' <wind_haz_mit(--nospam--at)>
Date: Monday, September 13, 1999 1:19
Subject: [wind_haz_mit] Re: Fw: Wind Tunnel Testing

>Mr. Cohen:
>In a short answer - I would say definitely yes that wind tunnel testing
>would be in order for this type of structure.  The relatively high
>aerodynamic drag of the cables (about 8 times that of a neutral airfoil of
>same cross section) and the associated vortex shedding should be
>mathematically modeled and then empirically tested.  The drag force on a 4
>in diameter (smooth) cable in a 100 mph wind is about 1000 lbs. per 100 ft
>and the vortex frequency would be about 90 Hz.  It would be interesting to
>see the architect's wind loading and effects analysis for the bridge.
>Where?  Depends on what scale and what speeds.  NASA Ames Research Center
>has a tunnel with a 30 ft test section as well as others, and NASA's
>Research Center has a variety of tunnels with a variety of test sections
>speeds.  Several of the NASA tunnels are closed circuit where atmospheric
>pressure can be varied and several are wet tunnels where rain and icing can
>be introduced.  NASA's Glenn (formerly Lewis) Research Center also has
>similar capabilities.  Many universities also have smaller tunnels that
>could do nicely for first order effects.  If I can provide any additional
>info, please don't hesitate to ask.
>Thank you for the info.
>Jan A. Zysko, NASA
>Kennedy Space Center
>407 867-6532
>> -----Original Message-----
>> From: JCohen [SMTP:jccpc(--nospam--at)]
>> Sent: Friday, September 10, 1999 4:54 PM
>> To: wind_haz_mit(--nospam--at)
>> Subject: [wind_haz_mit] Fw: Wind Tunnel Testing
>> Another item from SEAINT listserve FYI.
>> James Cohen
>> James Cohen Consulting, P.C.
>> PO Box 130
>> Pennington, NJ 08534
>> Tel: (609) 730-0510
>> Fax: (609) 730-0511
>> Website:
>> -----Original Message-----
>> From: Caldwell, Stan <scaldwell(--nospam--at)>
>> To: 'SEAint Listserv' <seaint(--nospam--at)>
>> Date: Friday, September 10, 1999 16:06
>> Subject: Wind Tunnel Testing
>> >In the very near future, Halff Associates expects to begin designing a
>> >series of "signature" bridges in concert with Santiago Calatrava of
>> Zurich,
>> >Switzerland.  These bridges are envisioned to be steel arch and cable
>> >structures, with concrete decks spanning from 800 feet to 2000 feet.  If
>> a
>> >picture is worth a thousand words, the bridge model photographs at
>> >
>> > "What's New?"
>> >
>> >should be worth several paragraphs.  The first bridge will probably be
>> >eight-lane divided structure with twin arches, each spanning about 800
>> feet.
>> >Several questions have been raised concerning wind tunnel testing of
>> >structure.  Since I do not have first-hand experience with wind tunnel
>> >testing, I request your collective wisdom in answering these questions:
>> >
>> >1. Is wind tunnel testing appropriate and necessary for this type of
>> >structure?
>> >
>> >2. Where in North America could these tests best be conducted?
>> >
>> >3. What would be the approximate (order of magnitude) cost for this
>> >testing?
>> >
>> >Thank you in advance for your thoughts on this matter.
>> >
>> >Stan R. Caldwell, P.E., F.ASCE
>> >Vice President, Structures
>> >***************************************
>> >Engineers*Architects*Planners
>> >8616 Northwest Plaza Drive
>> >Dallas, Texas  75225
>> >Phone:    (214)346-6280
>> >Mobile:   (214)236-9696
>> >Fax:      (214)739-0095
>> >Email:    scaldwell(--nospam--at)
>> >Website:
>> >***************************************
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