# Wind velocity input

Can anyone provide an explanation about the input wind velocity?

Having the weather data measurements, and taking that usually wind is measured at 10 mt height is this the input to give in Vasari?

Thank you for pointing out the discrepancy on the wind rose units, I have filed a bug.

As for height, our weather data is measured at 10m. However, the Wind Tunnel does not currently take into account for the effects of wind at different real world heights. The point of moving the 2D "slice" up and down is to study the local effect of the wind at that point based on the effect of the wind inside the 3D boundary conditions (assuming you are using 3D calcs.) At this point, the only connection between the Wind Tunnel and the weather data is the latter sets the default wind speed and direction based on historical data (not height.) as per the wiki page I posted above. Keep the questions coming! It is great to see people really "kicking the tires" (as we say in the U.S ;-)

Thanks Tom.

I got it. But i need to tell you that i find somethings inconsistent. I'm taking as an example one place that i know for sure it's wind characteristics: Tel Aviv. I know that the predominant wind blows from west, North-West on summer, and that the average velocity (roughly) can be taken as 5 m/s (measured at 10 m height). The units in the rose wind are transposed between km/h and m/s. Otherwise i can't explain the velocities that Vasari is using and showing. I also get to this conclusion looking at the numbers and units in the wind rose. For example, 6 km/h shows 20 m/s, and should be 1.66 m/s.

In the same topic, i have a question just to understand. I will assume that your weather data is measured at 10 m height. If so, when i show the winds at a different height (for instance 50 m) is the wind velocity shown in the simulation fixed to that height, or is it he velocity measured at the weather station? Either way, it is unclear and i suggest further explanations for that.

I have plenty more questions but i'll leave it here by now so maybe you want to answer just a few ones each time :-)

Thanks again and keep this good work on.

When you first launch the Wind Tunnel feature, it sets the initial wind speed and direction based on your project location historical wind data taken from our climate server. The initial speed and direction assume the highest frequency wind speed and direction assuming the span of an entire year. To refine this, click Detailed Wind Analysis, which will launch the Wind Rose. As you refine the target month(s) and time(s) of day, you will see the overlay graph on the Compass Slider update. You can then use the Compass Slider to begin to explore the effects of different wind speeds and direction.

see this wiki page for more detail. Give it a try and give us feedback on your experience.