WaSP Engineering 2.0 and turbulence

[bepi]

Hello all,

I'm a user of Weng2.0 mainly for inflow calculation now I'm trying to model turbulence as I usually do with WindPRO. I'm used to inserting standard deviation of the wind speed along with wind speed in WindPRO and as someone already knows doing that we can get statistic report of turbulence intensity.

Is it possible to do the same with WEng? Or should I use other application like Wasp Climate analyst?

The "Help" says that it is possible to choose between 3 different spectral models and 3 different terrain types...but are we dealing with the actual wind speeds fluctuation we have at the meteorological mast (i.e. measured values)?

Thanks in advance

[Morten]

Hi Bepi,


I am not familiar with the WindPro turbulence model, but in WAsP Engineering the standard deviations of the wind speed is a model result and not an input. The input is a reference mean wind speed and direction plus the terrain elevation and surface roughness map. An important limitation of the WEng turbulence model is that it cannot model effects of variable stability or random effects of measurements with 10-min sample duration. This introduces some differences at low wind speeds.


A good description of the WEng turbulence model is found in “Mann (2000) The spectral velocity tensor in moderately complex terrain, J. Wind Eng. Ind. Aerodyn. 94 (2006) 581–602”


Best regards,
Morten Nielsen

[bepi]

Hi Morten,

first thanks for your answer. Well, I was just referring to the WindPRO calculation which consists in dividing standard deviation by wind speed (both measured with anemometers) and plotting the Turbulence Intensity coming out from this calculation with wind speed. Basically as far as I can understand while with WindPRO we can handle measured turbulence in WEng we have "simulated" turbulence as it comes out with a particular terrain model (.map) and roughness, right?
Giuseppe

[Duncan]

Bepi, Morten is on holiday for a couple of weeks. I'm sure he'll get back to you with a full answer, but meanwhile I can confirm that WEng is generating simulated turbulence statistics. The velocity derivatives from the flow model (LINCOM)are used to simulate the turbulence at a site, and this is carried into the WAT calculations.
Duncan

[bepi]

Hi Duncan,


thank you. This is most interesting. So it's WAT which calculates turbulence, not WEng

[Duncan]

No, it's done in WEng. The results of the turbulence simulation are saved to file and used by the WAT later.

[bepi]

Ah ok Duncan thanks for explanation

[Morten]

Hi Giuseppe,


WAT is using the WEng turbulence estimates to calculate the the special turbulence measure needed for an IEC site assessment. Read more on this in my post today at http://www.wasptechnical.dk/forum/viewtopic.php?pid=1455#p1455


Best regards,
Morten