CFD results

[Janst1]

Hi Wasp Team,

I have done a WASP CFD calculation. The results are looking quite good but I would like to know the following issues.

1. How can I extract the speed ups and turbulence values into an excel sheet at turbine position. I want to do further analysis therefore I want to know if there is a possibility to extract the data.

2. The calculated turbulence intensity can be understood as mean value at 15 m/s?

Thanks for your answers in advance.

Regards,

Jan

[Duncan]

Hi Jan,

Sorry we didn't reply sooner.

To get the speedups to Excel, you can go to the 'Site effects' tab on the turbine site window and just CTRL-C to copy them all to clipboard. They should render nicely if you paste them to Excel

I will pass on your question about the reference speed for turbulence intensity to my colleagues.

Duncan.

[Brian Ohrbeck Hansen]

Hi Jan,

Here's a WAsP turbulence intensity example - simulating the Bolund case:

In the wake of Bolund:

- The speed-up factor from the WAsP CFD result file, A = U/Uref = 0,3066
- The turbulence from the WAsP CFD result file is K = sqrt(TKE)/Uref = 0,1658.

Uref is the wind speed at the inlet of the computational domain.

WAsP will give the turbulence intensity as 0,1658/0,3066 = 0,54 = 54 %
WAsP will truncate the turbulence intensity at 100 %

The speed-up factor and the turbulence from the WAsP CFD result file are both wind speed independent (WAsP CFD calculations are Reynolds number independent). Therefore, the turbulence intensity given by WAsP is wind speed independent as well.

Also, the turbulence intensity calculated by WAsP CFD represents neutral atmospheric conditions. The atmosphere generally approaches neutral conditions for high wind speeds, so the calculated turbulence intensity should represents these cases.

Cheers,

Brian

[Burock82]

Hello WAsP Team

i have another question regarding to CFD results. I can use the WAsP-CFD via WindPro so how i can export to result as excell or at least in the format which can be converted to excel or txt.

Thanks a lot

Regards,

Burak

[Burock82]

Hello WAsP Team

i have another question regarding to CFD results. I can use the WAsP-CFD via WindPro so how i can export to result as excell or at least in the format which can be converted to excel or txt.

After changing the extension to .zip i can see a lot of grid files but i can not use them.

Thanks a lot

Regards,

Burak

[Burock82]

Still No answer?

[BPal]

Hi WAsP Team,

I'm analyzing different turbulence models for my thesis, and I'm looking for a way to extract the TI values at specific positions, in my case the met mast positions, from the WAsP CFD models. Is there a simple way to extract this information from the .grd files in the .CFDRES folder? Or maybe there's an existing script that can be run?

Thanks in advance.

Brigette

[Duncan]

Hello Burock82, BPal,

Sorry that your posts have gone unanswered until now.

Borock82, I don't really understand what you're asking about here. Do you mean that you want to extract data from the CFDRES file directly and insert it to Excel? That's what BPal is wondering about.

It's true that the RES file is a ZIP archive which consists internally of a lot of different Surfer-format GRD files which are quite clearly labelled. You could easily extract these from the RES archive and display them in Surfer.

However, If you extract any data from the CFDRES file yourself and use it for something, then you're on your own: that's not WAsP output. There are some non-trivial interpolations and other checks being made in the code which interprets the contents of the CFDRES file for display and downstream use in the WAsP software. This code is running inside both WindPro and WAsP.

To get a site result, you should work with the GUI or scripting interfaces to extract what you need from our modelling objects.

In the met. station window, you can see the turbulence intensity for each sector on the site effects tab.

Does that answer your questions?

Duncan.