Wind Speed Correlation

[NOLAengineer]

Does anyone know a wind speed vs height correlation? A reference would also be appreciated.

 

[pennpiper]

Have you tried Google?

I did "wind speed vs. height"

and got many including this:

http://www.baywinds.com/new/tableestimated.html

 

[bchoate]

If you know wind velocity at a height (an average value, etc.) then the wind velocity at a height can be calculated base on the two heights and a velocity by the following:

v = (h/h(0))^alpha * v(0) where v = velocity, m/s; h = height, m; and alpha = wind shear exponent.

Consider the following reference:

http://www.engineeringtoolbox.com/wind-shear-d_1215.html

 

[Flareman]

NOLAengineer
A good reference is the current design wind code for the USA, ASCE-7. Winds are usually referenced at 10 meter elevation. The wind exponent essentially measures the drag created by the various aspects of surface roughness generated by objects on the ground. Once you reach a certain height (I think it's around 1000 ft) all winds are the same.
Note that the wind exponent can also vary with the sampling time used as a reference. Most jurisdictions have moved to a common standard of "3 second-gust" but much of the available historic data is derived using an older and more arcane standard called "fastest mile" (originally used in ANSI 58.1) and the relevant reference wind speeds and factors vary between the two methods. Typically, wind speeds referenced using "fastest mile" are numerically lower than those using "3 second gust" even though they are essentially the same condition.

David

 

[JLSeagull]

Generalizations may exist for plant design but too many variables exist for precision. Wouldn't the surface and 100-foot winds be very different among the plains of Kansas, the mountains of Colorado, beaches of Florida and the lake near Chicago?

Check the actual and forecast winds to verify the generalizations posted. The site posted below includes the wind forecasts for each 3000 foot from the surface to flight level 480 (48000 foot) for flight planning.

http://adds.aviationweather.noaa.gov/winds/

 

[BigInch]

thread507-159716


**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[mbeychok]

NOLAengineer:

Send me your email and I will send you the detailed formula (and how to use it) that has been fairly widely accepted by air pollution disperaion modelers for the last 30 to 40 years.

I am not allowed to give you my email on this forum but a Google search should find it for you.

Milton Beychok